The injection and storage of supercritical CO2 (scCO2) have been conducted in fractured sandstone reservoirs at In Salah, Algeria and Snøhvit, Norway, and planned in fractured sandstone, carbonate, and dolomite reservoirs at Longyearbyen, Norway, Hontomin, Spain, and Kevin Dome, USA, respectively, with matrix permeability varying from 0.01 to 60 md. For densely fractured reservoirs with low...
One gram of soil can contain up to 100 million to 1 billion microrganisms and up to 1 million different species of microorganisms. Despite this fact, geotechnical engineers have, until fairly recently, ignored biological activity in the soil or possible biological amendments that could be introduced. Over the last ten years research has focused on bioaugmentation strategies (i.e. the injection...
The effectiveness of bentonite clay as a wellbore plugging material often depends upon its penetration into near-borehole cracks associated with the drilling process. Here we present research aimed at understanding and maximizing the ability of clay materials to plug near-borehole cracks. A device was constructed such that the borehole is represented by a cylindrical chamber, and a...
Wettability is a paramount factor in multiphase flow through porous media. The preference of the rock mineral surface to oil or brine determines fundamental flow functions in reservoir engineering like irreducible saturations, critical saturations, relative permeability and capillary pressure. Its implications affect all processes in oil and gas recovery, from primary production,...
The Brazilian Synchrotron Light Laboratory (LNLS) is currently engaged in the construction and development of Sirius, the largest and most complex scientific infrastructure ever built in Brazil and one of the first 4th-generation Synchrotron Light Sources in the World. Its ultra-low emittance (0.28 nm.rad) and high brightness will allow the execution of very competitive experiments, opening...
A recent experimental study [Herring et al., 2016] shows the potential of enhancing residual trapping of supercritical CO2 (scCO2) via cyclic injections. Two competing mechanisms were identified that impact residual scCO2 trapping: (1) the wettability of solid surfaces is altered due to direct contact with scCO2; (2) different capillary pressure results in different initial states of scCO2...
Seepage properties of porous media such as flow resistance, permeability, starting pressure gradient, gas flow and diffusion, and imbibitions have been received steady attention for decades in the area of pore-fractured porous media (PFPM) such as oil/water/gas reservoirs, hot dry rocks etc. The pore-fractured porous media, which consist of irregular pores in matrix with embedded fracture...
Unlike conventional reservoirs where pore size distribution has a micrometer scale (Nelson 2009), tight oil and shale gas reservoirs have predominantly mesopores (between 2 and 50 nm) and micropores (below 2 nm). Volume fraction of micropores is not negligible and can be as high as 20% (Kuila et Prasad 2011). As hydrocarbon molecules range between 0.5 and 10 nm (Nelson 2009), interaction...
Investigating the mechanisms that govern flow of fluids at the pore-scale are the cornerstone of understanding multiphase flow in porous media for a wide range of applications, including hydrocarbon recovery, CO2 sequestration and contaminant hydrology.
Microfluidic devices, coupled with visualization techniques allow us to study pore-scale processes [1, 2]. Glass substrates are often...
Multiphase flows in disordered porous media have a significant influence on many industrial applications, such as unsaturated soil mechanics, carbon geo-sequestration, and oil recovery. In this paper, we discuss two aspects of the problem, namely, (1) wettability at dynamic conditions and (2) disordered microstructures.
First, to simulate surface tension, wetting effects as well as dynamic...
Natural gas production from shale formations has received extensive attention in recent years. While great progress has been made in understanding the adsorption and transport of single-component gas (usually CH$_4$) inside shales’ nanopores, the adsorption and transport of multicomponent shale gas under more realistic reservoir conditions (e.g., considering CH$_4$/C$_2$H$_6$ mixture) only...
Injection of CO2 deep underground into porous rocks, such as saline aquifers, appears to be a promising tool for reducing CO2 emissions and the consequent climate change. During this process CO2 displaces brine from individual pores and the sequence in which this happens determines the efficiency with which the rock is filled with CO2 at the large scale. The aim of this work is to better...
Pressure-driven flow within the plane of a confined thin porous medium takes place in a number of natural and industrial processes. This includes flow during manufacturing of fibre reinforced polymer composites with liquid moulding processes, passive mixing in microfluidic systems and paper making. The thin porous media considered here is a simplified, well-structured model of a porous media...
Over the past decade, laboratory based X-ray computed micro-tomography (micro-CT) has given unique insights in the internal structure of complex porous materials in a broad range of applications, improving the understanding of pore scale processes and providing vital information for pore scale modelling. The non-destructive nature of micro-CT imaging, combined with dedicated X-ray transparent...
The heterogeneous nano-scale pore structures have a significant effect on hydrocarbon properties and matrix mechanics in shale. Marine and lacustrine shales may have varying pore structures due to different depositional settings. Understanding the nano-scale pore structures in marine and lacustrine shales can provide important insights into fractal geometry theory. Therefore, we use the...
We examine the linear and weakly nonlinear stability analyses of the dissolution-driven convection induced by the sequestration of carbon dioxide in a geological formation. The mathematical model consists of Darcy's equation, the conservation of mass and the conservation of solute equations. The model accounts for anisotropy in both carbon diffusion and permeability which is modeled by a...
Numerical simulations of injection of CO2sc or of a mixture (aqueous solution + CO2sc) in sandstone cores were carried out. These preliminary numerical tests have twofold targets: i) helping for designing lab experiments and to anticipate the experimental behaviors of such complex systems and ii) to explore complex conditions (flow-pressure-temperature-salinity) that could not be easily...
Abstract
Understanding the gas occurrence states under real reservoir conditions is the prerequisite to study the mechanisms of gas flow in shale reservoirs, in which large amounts of nanoscale organic pores exist. Besides, water is inevitable when considering the gas flow in shales. Thus molecular dynamics simulations were performed to study the occurrence states of gas-water mixtures...
Bio-mediated ground improvement technologies harness subsurface biological and chemical reactions to improve the engineering properties of soils with reductions in detrimental environmental impacts when compared to conventional methods (Seagren and Aydilek 2010; DeJong et al. 2013). One such technology, Microbially Induced Calcite Precipitation (MICP) or bio-cementation, has received...
Cement failure in subterrenean wells may compromize zonal isolation, cause corrosion of steel casing and, in the worst case scenarios result in a catostrphic event of well collapse. Portland cement and its blends are used for cementing the majority of subterrenean wells. Although they proved to provide a robust solution in many cases, they are not durable in aggresive environments with high...
An interface of phase transition is a macroscopic surface that separates the domain occupied by a single-phase gas or liquid from another domain occupied by two-phase gas-liquid mixture. In classical fluid dynamics an example of such a surface is the boundary of a cloud or a spray in the air. In porous media, this corresponds to the injection of miscible gas in an oil reservoir, which creates...
Gas production from unconventional source rocks, such as ultra-tight shales, has increased significantly over the past decade. However, due to the extremely small pores (~ 1-100 nm) and the strong material heterogeneity, gas transport in shale is still not well understood which poses challenges for predictive field-scale simulations. In recent years, digital rock analysis has been applied to...
• Theoretical part of this work has just been accepted by Physical Review Letters
Long-term storage is necessary in order for CO2 geological sequestration in to be feasible. Leakage of CO2 by buoyant forces may occur if the trapping of CO2 in porous media is not stable with formation of large CO2 clusters. Ostwald ripening is a well-known phenomenon in two-phase mixtures that may affect...
All wells will one day need to be permanently plugged and abandoned (P&A'ed), and this last phase of a well's life cycle does not end – but has an eternal perspective. The North Sea is a mature petroleum region, and a heavy focus on P&A activities are planned here for the next decades. Research and technology development needs to keep up with this shift in activity level, and a strong focus...
Microbially Induced Carbonate Precipitation (MICP) through the urea hydrolysis reaction has been extensively studied in the lab and implemented at field-scale several times, most notably for fracture sealing (Cuthbert et al., 2013; Phillips et al., 2016), for erosion control (Gomez et al., 2015), and for ground improvement (van Paassen et al., 2010). Grouting strategies used in industry are...
Fuel Cell is considered one of the promising technology which can be utilized in many different applications, such as stationary, transportation, and portable usage. One of fuel cell efficiency limitation is water flooding at the cathode gas diffusion layer (GDL) at high current densities or low operating temperatures. There are many different experimental and theoretical studies regarding...
Recent years, tight oil and gas has become a very important and reliable replacement for conventional energy. The porosity in tight reservoir is very small and there is a threshold pressure gradient (TPG) phenomenon and stress sensitivity in it, which make the fluid in tight reservoir hard to move and has a different employment law from the conventional reservoir, so we need a further...
Injection of CO2 into a saline aquifer leads to a two-phase flow system, including a supercritical CO2 phase and a brine phase. Various modeling approaches, including fully three-dimensional (3D) models and vertical-equilibrium (VE) models, have been used to study the system in unfractured formations. Three-dimensional models solve the governing flow equations in three spatial dimensions and...
Chemical enhanced oil recovery, specially surfactant-polymer flooding, involves porous media flows of simple and complex fluids through highly heterogeneous formations. We will discuss various models based on systems of partial differential equations which pose a variety of mathematical and computational challenges. We will start a dialogue on these challenges with some possible pathways to...
In this work, it is shown that the one-domain approach (Goyeau et al, 2003) can be used to model precisely the average fluid velocity in a channel partially filled with a porous medium. This conclusion is drawn from the comparison of the averages obtained from the solution of the effective transport equations, with position dependent coefficients, and the ones resulting by direct integration...
The effective mineral surface area is often the least well constrained variable in the prediction of geochemical reaction rates and, therefore, poses a large uncertainty when modelling reactive-transport in porous rocks. The mineral surface area is often estimated using a combination of microscopic and spectroscopic techniques or using disaggregated sediment in dissolution experiments. Both...
Pore-network modelling is an efficient method to simulate pore-scale multi-phase flow. The pore-network consists of a collection of idealized interconnected discrete network elements – pore nodes and pore throats. Capillary-dominated flow is modelled based on invasion-percolation rules. Although pore-network modelling is much less resource-demanding than direct simulation approaches, current...
A novel approach is suggested to simulate the gas mixture transport in slit nanopores. The proposed method is based on the modification of the dual control volume grand canonical molecular dynamics (DCV-GCMD) method. The conventional method, DCV-GCMD, describes the gas mixture transport with pre-set constant composition. Due to the selective adsorption in the nanopores, the composition of the...
Injection of carbon dioxide (CO2) into deep geologic formations has been widely proposed as an effective way for the permanent storage of CO2. Modification of the interfacial properties of CO2 in minerals by using surfactant has been proposed aiming on increasing the mobility of CO2 through porous media. Surfactants are proven to effectively alter the interfacial tension and wettability in...
Thermally induced cracks can be created when cold fluid contacts a higher-temperature rock. When rock is dry, it first contracts locally near the fluid/rock interface and then fractures in dominantly in tensile mode. However, when rock is saturated or partially saturated with water, the pore water in a rock complicates the behaviors because expanding freezing pore water may interact with...
A series of canister desorption tests were carried out on 31 deep (over 3000 m) over-mature Lower Permian-Upper Carboniferous shale cores under atmospheric pressure and at reservoir temperatures of 75 and 80 °C, as well as a higher temperature of 95°C. Organic chemistry and X-ray diffraction were combined to investigate the impact of composition on canister desorption behavior. In order to...
We report a study of heavy oil recovery by combined water flooding and electromagnetic (EM) heating at a frequency of 2.45 GHz used in domestic microwave ovens. A mathematical model describing this process was developed. Simplified model equations are solved analytically and the solution is presented in an integral form for the one dimensional case. Complete model is solved numerically using...
The biogenic gas behavior in porous media, which includes bubble nucleation and growth, migration, coalescence and trapping is affected by the gas generation rate, distribution of reactive sites and the pore scale characteristics of the sediment. In this study, experiments are performed using a micro-fluidic chip in which different gas bubble behavior mechanisms in the porous media are...
While quasi-static pore network models (PNM) have been used to investigate the relative permeability (Kr) behaviour of reservoir rocks since the seminal work by Bakke and Øren (1997), the capacity of these models to capture the appropriate physics and predict experimental data remains contentious (Sorbie and Skauge, 2011; Bondino et al., 2012; Berg et al., 2016). It is generally accepted that...
The Bunter sandstone formation in the Southern North Sea and the Captain sandstone formation in the Northern North Sea represent two of the largest potential CO$_2$ stores in the UK, with estimated capacities of up to 14 Gt and 1.7 Gt respectively [1, 2]. With current UK CO$_2$ emission totalling ~400 Mt/yr [3], the Bunter and Captain formations alone have the potential to store UK emissions...
Ancient stone relics and historic buildings are often subject to significant degradation. The protection and restoration of these monuments is extremely urgent. Here, a method of building repair based on microbial induced carbonate precipitation (MICP) has been tested on marble stone. In previous research, microbial mortar (stone powder treated by MICP) was tested as a filling material to...
CO$_2$ injection into a saline aquifer leads to a two-phase flow system (supercritical CO$_2$ and brine), which often involves large spatial and temporal scales that require high computational cost. To address the computational challenge, in the past decade, a series of simplified models based on vertical integration of the full multi-dimensional governing equations have been developed. These...
Wicking as imbibitional flow of a liquid driven by capillary pressure has been an important topic in different areas from simple applications like air refreshers and lightening torches to high-tech one such as Propellant Management Devices (PMD)[1, 2]. In this research, wicking of a liquid into porous wicks made parallel fibers is investigated. In the first step, we developed a model for...
The capillary entry pressure (Pce) and corresponding pore throat size control the thickness of an oil or gas column that may be sealed beneath a mudrock. Mudrock seals typically have nanometer-scale pore throats, and the Pce often exceeds the minimum horizontal effective stress in these rocks. Mudrock seals can fail through fracturing either by buildup of fluid pressure or during faulting or...
Wettability is a major factor that controls the evolution of interfaces during immiscible fluid displacement from a permeable medium. Three dimensional imaging by ultrafast X-ray tomography allows us to investigate the morphology at different wetting conditions and relate it to the prevalent pore-scale process. In this study we focus on the evolution of the fluid interfaces in random piles of...
Shale gas has redefined energy landscape[1]. The United States (U.S.) natural gas production is expected to increase every year, and in 2035 the U.S. shale gas production may raise to 50% of the total gas production.
Shale rock consists of micropores and mesopores[2]. It is also composed of inorganic minerals (quartz, clays, calcites, and feldspars, etc.) and organic matter (kerogens and...
Worldwide demand for new and sustainable approaches to geotechnical engineering problems has generated novel research opportunities in the emerging field of bio-mediated soil improvement. The most widely researched of these processes is microbially induced calcite precipitation (MICP), which has shown promise for a wide variety of engineering applications. Initially MICP was accomplished by...
Enhanced oil recovery testing often relys on either a sand pack filled with sand or use Berea sandstone that doesn’t take into account the full range of petrophysical properties of the actual reservoir. Among the most important reservoir petrophysical properties are the particle sizes and their distribution that serves as the key parameter that influences strongly other key petrophysical...
Understanding the relation between CO2 saturation/distribution and velocity/attenuation of acoustic wave propagation is fundamental for an accurate and reliable quantitative interpretation of (seismic) CO2 monitoring data.
Quantitative interpretation of geophysical data requires understanding of the relationship between the physical properties of the rock, the microstructure of the rock, and...
We study immiscible fluid-fluid displacement in rough-walled fractures with a focus on the combined effect of wettability, the viscous contrast between the two fluids, and fracture surface topography on drainage patterns and interface growth. We have developed a model to simulate the dynamic displacement of one fluid by another immiscible one in a rough geological fracture; the model takes...
The porous pore doublet model that was published in 2008 [1] is presented and discussed. The background to the model is that fabrics used for fiber reinforced composite manufacturing often consist of fibers gathered in bundles.Thus, during manufacturing, the liquid resin impregnates a multiscale porous medium and there is a transport between pores of different scales driven by an applied...
We developed a sharp-interface level-set method for immiscible pore-scale two-phase flow with a thin wetting film on the solid surface. The lubrication approximation is used to model the thin-film equation efficiently. The incompressible Navier–Stokes, level-set, and thin-film evolution equations are coupled sequentially. Hamilton–Jacobi level-set reinitialization is employed to construct the...
The complex fluid flow processes occurring during EOR methods are difficult to implement in numerical modeling. Therefore, this presentation aims to share some light on experimental results from microfluidics studies conducted for various multi-phase fluid displacement processes with a focus on chemical EOR methods using brine, polymer-, alkaline- and surfactant-solutions. A wide range of...
The behavior of CO2 inside a reservoir (i.e., two-phase flow in CCS, or three-phase flow in CCUS) is influenced by interfacial tension, pore structure, wettability and other reservoir parameters (e.g., pressure gradient), which vary significantly from one reservoir to the next. Therefore, understanding multi-phase flow under various reservoir conditions is crucial to estimating CO2 storage...
Considering the paradigmatic case of random piles of spheres, fluid front morphologies emerging during slow immiscible displacement with a global front velocity of 3 µm/s are investigated in real time by X-ray micro–tomography and quantitatively compared with model predictions. Controlled by the wettability of the bead matrix two distinct displacement patterns are found with a transition...
Nonaqueous phase liquids (NAPLs) are still a major challenge for all traditional groundwater treatment technologies. NAPLs often contaminate the subsurface following an accidental spill or due to a defect in the oil storage tank. These pollutants remain trapped in the form of droplets and / or immiscible clusters within the aquifer, thus constituting a persistent source of pollution that is...
The oil displacement effect of polymer flooding is mainly governed by the rheological property of polymer in the deep reservoir, while the mechanical degradation is one of the key factors affecting its rheological properties [1]. Polymer molecular chains can be mechanically degraded in shear flow and extensional flow, which both involves in the flow through a porous medium. Mechanical...
Characterizing dissolved chemical migration in porous media through the Advection Dispersion Equation requires the knowledge of the fluid velocity field and of dispersivity values associated with diverse geomaterials which can make up the internal architecture of the system. Several studies have focused on the assessment of the impact on solute concentration dynamics of an incomplete knowledge...
Fine-grained sedimentary rocks, such as mudstones and shales, contain abundant nanometer- to micrometer-sized pores. These narrow pores create intense fluid-rock interaction that may lead to complicated fluid storage and transport process. Concerns about the accurate evaluation of gas content and diffusion kinetics have led to many experimental studies about gas sorption on shales. However,...
Liquid foams are a proposed solution to overcoming conformance issues while increasing apparent viscosity over gas/water only injections in petroleum reservoirs. However due to the diversity of flow behaviour foam flow in porous media providing a sufficiently accurate and low uncertainty model for industrial use can represent a significant challenge. Understanding the specifics of foam flow...
Turbulence in porous media is a phenomena that is more prevalent than commonly thought. Such flows happen in packed bed reactors (e.g., oxidation of petrochemicals), in pebble-bed nuclear reactors (where Reynolds numbers can be on the order of 100,000), and at the fluid-solid interface of rivers to name a few examples. One of the characteristics of turbulent flows is the notable deviation...
Solute transport in porous media is important for several industrial applications, i.e.: hydrology, building stone performance and waste management. Spreading and mixing during solute transport is significantly impacted by the pore scale heterogeneity found in natural porous media, which complicates upscaling (Dentz et al., 2011). Therefore, simulations and experiments which investigate the...
Phase change at the nanoscale is critical to many industrial applications including rapidly emerging unconventional oil and gas production from nanoporous shale reservoirs. The thermodynamic behaviour of hydrocarbons confined to these nanopores is expected to deviate significantly from bulk properties and there is little experimental data to validate theories. This research aims to visually...
We describe recent advances in pore scale dynamics direct numerical simulation. The Volume of Fluid method associaed with well-balanced surface tension methods allows for the simulation of low capillary numbers. Further progress should involve thin film and corner flow formation, contact line dynamics and efficient combinations of parallelism and grid adaptation.
This ensemble of...
Multiphase flows in porous media play an important role in many natural and industrial processes, such as transport mechanisms in the vadose zone, CO2 sequestration in saline aquifers or oil recovery in petroleum applications. The traditional picture for such flows is one at low Reynolds number where the distribution and flow of the different phases is controlled by interfacial energies of...
Foam injection is believed to be a promising technique to enhance oil recovery. One of the key characteristics of the foam and its rheology in porous media is its texture which describes the spatial distribution and size of the gas bubbles. Yet, the description of the texture of a foam confined in a real porous medium is a challenging issue because conventional methods do not have adequate...
We consider the problem of advection, matrix-diffusion and bimolecular reactions in fracture-matrix systems, with two example applications: (i) Weathering reactions in fractured bedrock and (ii) in-situ chemical oxidation (ISCO) for remediation of fractured rock. In both cases, a reagent (a weathering agent such as H+ or dissolved oxygen, or permanganate in the case of ISCO) are supplied...
Urbanization in coastal areas has been on an increasing trend during the last century. In some coastal regions, groundwater is one of the major source of potable water for the population, the industry, and the agriculture with an average demand of 30 m3/s [1,2]. Sea-level rise has been recorded to be approximately 40 mm/yr [3] with the potential consequence to favor significant intrusion of...
Shear-thinning fluids flow in the rough fracture is encountered in numerous industrial applications such as hydraulic fracturing fluids flow in rough hydraulic and natural fractures to carry the proppants, polymer gel extrusion through rough fracture to reduce excessive water production in naturally fractured reservoirs, CO2 sequestration and leakage through rough fractures, etc. We...
The injection of substrates, e.g. hydrogen with the purpose of energy storage, into subsurface structures could stimulate the growth of all present microbial species which are able to use this substrate for their metabolism. The linkage between transport, the growth of microorganisms, substrate availability and biodegradation results in a strongly coupled dynamic system. The difficulty in the...
We study the Lagrangian dynamics of steady three-dimensional (3D) Stokes flow over granular media consisting of simple cubic (SC) and body-centered cubic (BCC) lattices of closed-packed spheres, and uncover the mechanisms governing chaotic fluid advection. Due to the cusp-shaped sphere contacts, the topology of the skin friction field is fundamentally different from that of continuous...
Experimental measurements of electrical resistivity of synthetic rocks with confining pressures up to 1700 bars and 200°C were performed in a high pressure cell to evaluate how the correlation between size pore distribution and brine composition is [1]. The porous media were manufactured with homogeneous glass beads and were saturated with different salt concentrations brines. According to our...
Model improvement by conditioning on data collected at multiple scales remains a challenge in complex settings. We employ an information-theoretic approach that allows for seamless integration of multi-resolution data into multi-scale simulations to upscale conductivity of heterogeneous formations. Fine-scale information is summarized into a coarse scale representation by setting a...
Foam can improve sweep efficiency in gas-injection enhanced oil recovery. Surfactant-alternating-gas (SAG) is a favored method of injection, in part because of excellent injectivity during gas injection. However, liquid injectivity is usually very poor in a SAG process, and fracturing of the well can occur. We report a coreflood study of liquid mobility under conditions like those near an...
Objectives:
CO2 injection, as one of the effective techniques for enhancing recovery of shale gas, has been widely used and proved economically available. In shale, clay minerals play an important role on methane adsorption due to its large volume of micropores. So far, however, a few attentions have been paid on competitive adsorption of CO2/CH4 Mixtures on clay minerals. In this study, we...
Among the known EOR techniques which have been investigated and tested during last decades the solvent injection proved to reach one of the best recovery factors. From the other side the solvent retention problem makes it relatively expensive and thus less attractive. So the successful practical application of solvent having only an active EOR agent has not been frequently reported.
...
Unconventional plays like the Bakken petroleum system (BPS) are the main reason behind the U.S. oil and gas industry renaissance during the last decade. In that period, more than 10,000 wells have been drilled in the Bakken alone, most of them targeting low or ultralow permeability strata. While the hydrocarbon in-place estimates are in the order of hundreds of billions of barrels, most...
Steam injection has been implemented with residual oil saturation in swept zones being as low as 10% in the case of Steam Assisted Gravity Drainage (SAGD) processes. The primary difficulty with a gas injection of any kind is conformance due to low density and viscosity of the gas. Therefore, gases tend to form channels and pathways through oil rather than displacing the oil. Traditionally...
Few current bioreactive transport solvers currently provide a comprehensive mechanistic description of biogeochemical cycles and allow easy integration of all the involved processes, including flow in variably saturated media, solute transport and kinetic/equilibrium biochemical reactions. The parameterization of these processes is particularly challenging since our knowledge of model...
The highly compressible nature of some aquitards leads to nonlinear consolidation where the groundwater flow parameters are stress-dependent. The case is further complicated by the heterogeneity of the hydrogeologic and geotechnical properties of the aquitards. To adequately model land subsidence in these systems, we develop a modeling approach to couple a nonlinear 1-D groundwater flow and...
Understanding how pressure fronts propagate (diffuse) in unconventional reservoirs is fundamental to transient flow analysis as well as reservoir drainage volume estimation. We have developed an alternative approach to the solution of the 3-D diffusivity equation by directly solving the propagation equation for the “pressure front” of the transient solution. The pressure front equation is an...
Life in porous media, as soil bacteria, are used since more than 40 years ago as bio-fertilizer contributing to the development of a sustainable agronomy. Even though they are extensively used due to their low cost, such biotechnology is still far from being efficient and many challenges are opened for basic research in porous media science.
Our microbiological system of study are the...
Below 2.17 K, helium no longer behaves as a classical fluid: it has almost no viscosity and a high effective thermal conductivity that is used to cool superconducting devices such as the Large Hadron Collider’s magnets. Beyond a critical velocity, quantum turbulence arises and complex flow patterns appear.
We developed a numerical tool to simulate helium superfluid flow in porous media at...
Chemicals in the form of nanoparticles or surfactants provide opportunities to improve oil displacement from rocks. They increase the rate of hydrocarbon recovery by breaking down the oil trapped in by-passed zones and separating the residual oil from rock surfaces in the form of tiny droplets suspended in the water phase. In this study, a series of heavy oil displacement experiments are...
Shakil A. Masuma*, Hywel R. Thomas
Geoenvironmental Research Centre, School of Engineering, Cardiff University, Cardiff, United Kingdom
*masumsa1@cardiff.ac.uk (corresponding author’s E-mail)
Sequestration of anthropogenic carbon dioxide in deep geological formations, such as, saline aquifers, un-mineable coal seams is a plausible way to reduce global greenhouse gas effects. Safety and...
The foam efficiency in the oil displacement processes is governed by foam stability which is generally reduced with the presence of oil. In this study, we investigate the effect of oil type and saturation on foam strength in Berea sandstone cores using coreflooding and nuclear magnetic resonance (NMR) imaging. Foam quality scan in the presence of remaining hexadecane showed higher apparent...
Semi-Analytical Particle Tracking Scheme For Advective/Diffusive Transport in Porous Media
The particle tracking scheme of David W. Pollock [Ground Water 26(6), 1988] provides a computationally efficient and mass-conservative method for Lagrangian transport in the absence of diffusion. In this work, a generalization of Pollock's scheme that allows for the inclusion of diffusion is...
Residual trapping is one of the key trapping mechanisms for CO2 geological storage, yet difficult to determine in-situ. The present study addressed determination of residual trapping over the entire range of scales from pore to core to field scale, based on data from Heletz, Israel [1] pilot CO2 injection site. During 2016-2017 two dedicated push-pull experiments have been carried out at the...
With the increasing demands for sustainable and eco-friendly soil improvement methods, utilization of microbial activities in subsurface has received increasing attention as an way to modify and control the mechanical and hydraulic properties of soils. Many bacteria can produce biofilms, which are matrices of organic materials consisting of microbial cells and extracellular polymeric...
Along with significant incentives to extract oil and gas from deep and unconventional resources, significant challenges exist in developing advanced technologies while being environmentally responsible. In this context, wellbore leakage and plugging is one of the key concerns that can affect both performance and environment. A similar leakage issue also relates to underground carbon storage...
Hard pellet model and capillary model as two types of physical models for porous media, can’t accurately describe the microscopic pore structure features of porous media. Shale rock porosity is dominated by nanometer and micron scales [1], the traditional models and methods can not accurately describe the pore structure of shale reservoirs. Numerous studies have shown that real porous media in...
Chemical flooding is one of the most promising EOR technique in both laboratory research and field trials. It has been applied in conglomerate reservoir as well as sandstone reservoir. To full understand the displacement mechanisms of chemical flooding in reservoirs with different lithology, it is essential to recognize the residual oil displacement in pore scale.
We selected three cores with...
Channel fracturing, as a novel technology, has reveived increasing attention in recent years due to its great advantage in promoting the fracture conducitivity as well as reducing consumtion of water and proppant. The open channels created by heterogeneous distribution of proppant are the priority path for oil or gas to pass instead of the pores exist in proppant pack. Since the flow pattern...
Mechanisms of pore gas transport and exchange across the porous medium-atmosphere interface in wind-exposed porous media was investigated for a range of porous media under different near-surface wind conditions.
Four dry porous media with mean particle diameters of 1.6, 2.0, 4.2 and 10.5 mm were used. These relatively coarse materials were selected, to facilitate easier identification of the...
Abstract: This paper further studied the pore throat model, by fractal equation with Forchheimer equation, obtained the analytical expressions of Darcy permeability, non-Darcy equivalent permeability, and the ratio of non-Darcy equivalent permeability and Darcy permeability. Darcy permeability is the function of porosity, average particle size, fractal dimension, is not the function of...
Fractures are ubiquitous in the subsurface, and provide primary pathways for fluids traveling underground. The roughness and wettability of the fractures in the subsurface cause a major impact on multiphase flow behavior. Nevertheless, published analytical solutions for multiphase flow properties of fractures fail to account for the complexity of the surface mineralogy heterogeneity and its...
Reactive transport in river corridors can be greatly complicated by fluctuations in the boundaries, which may cause changes from gaining to losing over time. The seasonal influxes of water cause wetting and drying of soils near the river, rainfall causes distributed periodic inputs to the surface, and chemical and physical heterogeneity affect the possible reaction sites. The combination of...
The storage and flow mechanisms in shales depend largely on their microstructure. We use two parameters to characterize microstructures, namely specific surface area (SSA) and pore-size distribution (PSD). We use N$_2$ adsorption at 77K to quantify SSA and PSD of nanopores. There are two limitations of the N$_2$ adsorption method due to (1) uncertainties in molecular area due to the quadrupole...
We present recent results relevant for an application of level set methods to track moving interfaces and free boundaries. We cover the most important tasks typically required in level set methods like an advection of level set function, a preservation of signed distance property, and an extrapolation of missing data in the normal direction to the interface.
Typically a movement of the...
Extensive Study of cement additive Gilsonite and its applicability to plug and abandonment application in the gulf of Mexico
One of the most economical and viable methods of soil improvement is dynamic compaction. However, dynamic compaction can only be applied on deposits where the degree of saturation is low and the permeability of the soil mass is high to allow for good drainage. The technique does not work very well on soils having a large content of fines. Also dynamic compaction produces lateral ground...
The petrophysical properties of rocks, such as thermal conductivity, electrical conductivity, and fluid transport, have been studied based on fractal geometry theory in many areas over several decades and determination of fractal dimensions is always the focus of researches and applications by means of fractal-based methods. In this work, a new method for calculating pore space fractal...
Accurate numerical simulations for density-dependent flow and transport model is one of the crucial keys for successful water resources management in coastal areas and on islands. However, traditional modeling approaches without special treatment may not be able to resolve accurate sharp moving fronts and corresponding groundwater flow velocities due to the numerical instabilities.
In this...
Deepwater horizon/Macondo event, which occurred on April 20, 2010, was one of the most catastrophic scenario in the United States deep waters. After that situation, regulations for drilling and completion projects became more rigorous and worst-case discharge calculations are mandatory as part of an Oil Spill Response Plan.
Drilling projects in deep water offshore is a huge investment for a...
The recent developments of microfluidic is offering a new and efficient tool to visualize transport processes of bacterial fluids from microscopic to macroscopic scales and assess the influence of well controlled environments. We explored a situation where the motility and pore geometry are the dominant ingredients influencing the hydrodynamic dispersion of a bacterial fluid.
To this aim,...
The seismoelectric and self-potential methods are showing promises to characterize both the vadose zone of the Earth, hydrocarbon reservoirs and CO2 sequestration. That said, the dependence of a key parameter, the streaming potential coupling coefficient, with the saturation remains highly debated. We explore here the relationship between the streaming potential coupling coefficient, the...
Urbanization in coastal areas can be a significant source of pathogenic microorganisms, such as viruses and fecal indicator bacteria. Recently, coastal water contamination is becoming an important issue due to global warming [1]. Viruses can migrate long distances though porous media, such as beaches and coarse sediments, because of their biological characteristics, i.e., their size and...
The size of the fractures and vugs ranges from micron scale to centimeter scale in frac-vuggy reservoir. And there is almost no flow in the rock matrix. Due to the multiscale of media, inertial coefficient is a key parameter to predict the correct production performances and behavior of frac-vuggy reservoirs. This paper introduced the process of making multiscale frac-vuggy media and will...
Setting a formation to formation cement plug in a well needing to be abandoned is a necessity, and the number of wells where this operation will have to be carried out increases each year in the North Sea. Paradoxically, where the mechanical and hydraulic integrity of this barrier matters most is also where these plugs are potentially weakest with today's placement methods. This is in the...
We consider log hydraulic conductivity (Y) as uncertain and predict steady-state groundwater head (h) through three different, independent approaches. The first two of them are based on the ensemble Kalman filter (EnKF), their difference being in the way statistical moments (SM) of state variables and parameters are estimated numerically before the Kalman filter is applied. Whereas in the...
A numeric model of non-reactive flow through naturally stratified sandstone samples is presented. This work is based on laboratory experiments in which it was established that solute migration in saturated stratified porous media was dominated by stratification. The experiment results strongly suggest that the effect of the stratification is dominant for flow parallel to the lamination in...
Studying the two phase flow model is of a great importance. It occurs in many fields of engineering such as oil recovery, the storage of nuclear wastes and the remedy of the groundwater infected naps. The mathematical formulation of this problem includes nonlinear partial differential equations. Moreover, various numerical investigations have been the object of the approximation of these...
Wicking is the capillary phenomena by which a preferentially wetting liquid is drawn into a porous medium due to surface tension forces. The Washburn equation, governing the spontaneous invasion of a wetting fluid in a capillary was developed in the early 1900’s. The equation can also explain a wide variety of impregnation processes in homogeneous porous media effectively. However, there are...
In areas contaminated by the petroleum industry, persistent compounds such as polyaromatic hydrocarbons (PAH) are often accumulated in the porous matrixes of sediments and soils (S&S), implicating risks to ecosystems and human health since these contaminants are released over time to interstitial and surrounding water. Pore size distributions (PSD) and PAH binding strengths to sorption sites...
In the middle-high permeability sandstone reservoir with strong heterogeneity and low permeability reservoir, invalid recycling of the injected water is formed along the natural high permeability belt and interwell fracture at high water cut stage, which results in reduction of reservoir recovery degree. According to the field tests, the reservoir recovery degree can be improved by coupling...
Unsaturated flow through thin layers of porous media are encountered in many industrial applications, including the liquid-absorbing hygiene products such as wipes, paper towels, and diapers [1-4]. These consumer products demand specific absorbent properties with storage of liquid playing a significant role. Understanding fluid flow and deformation processes in thin swelling porous media is...
This paper investigates through reservoir simulations the set-up of a foam EOR process in a real sector of a low permeability reservoir produced by waterflooding. The objectives are: to demonstrate our capability to simulate foam injection at field scale; to investigate the technical feasibility of foam injection in terms of injectivity, foam stability and improved oil recovery; and to analyze...
We report on an extensive investigation of solute mixing and spreading in reservoir rocks, including Bentheimer Sandstone (BS), Ketton Limestone (KL), Edward Brown (EB) carbonate and Indiana Limestone (IL), as well as unconsolidated bead pack (BP) as control material. We observe that the selected rock samples possess distinct strength of subcore-scale heterogeneity and present characteristic...
A domain decomposition algorithm is introduced to couple non isothermal compositional gas liquid Darcy and free gas flow and transport. At each time step, our algorithm solves iteratively the nonlinear system coupling the nonisothermal compositional Darcy flow in the porous medium, the RANS gas flow in the free-flow domain, and the transport of the species and of energy in the free-flow...
Direct measurement of shale gas adsorption isotherms at high pressures and high temperatures (HPHT) is intricate and requires expensive apparatuses. Most of the documented studies only report shale gas adsorption data at pressures below 12 MPa, which is much smaller than the reservoir pressure, e.g., up to 36 MPa in Eagle Ford shale. Recent studies also suggest that the excess adsorption...
Abstract
Random fractures widely exist in water/oil reservoirs, soils etc. Study of the permeability of the fractured networks has been one of focuses in the area of mass transfer in the past decades. Generally, the fractures in scale reservoirs distribute randomly and have statistical self-similarity and fractal characteristic. In this paper, the permeability model for gas flow in the...
In hydraulic fracturing of unconventional reservoirs, the stimulation fluid is injected at a different temperature than initial reservoir temperature. The dynamic temperature profile of stimulation fluid during the treatment can provide critical information for fracturing design. In this work, an analytical solution to model the stimulation fluid temperature profile during hydraulic fracturing...
Structural trapping is the ultimate barrier for reducing the risk of leaks at CO2 storage sites. Small pores in high specific surface clay-rich caprocks give rise to high capillary entry pressures and high viscous drag that hinder the migration of buoyant carbon dioxide CO2.
In this work we show measurements of the CO2 breakthrough pressure and ensuing CO2 permeability through sediment plugs...
Unconventional shale reservoirs with high organic content and swelling clays may have a high affinity for uptake of carbon dioxide (CO2). The pore space and mineral surfaces that sorb/contain petroleum are also potential sorption sites for CO2 and could become available for CO2 uptake once the reservoir is produced and depressurized. Understanding how shales interact with CO2 is important for...
Dimensional analysis applied to bacterial chemotaxis towards NAPL contaminants
Xiaopu Wang 1§, Beibei Gao 2§, Shuaiwei Gu 3, Wei Zhong 1, Kenneth S. Kihaule 1, Roseanne M. Ford 2*
1. National Engineering Laboratory for Subsea Equipment Testing and Detection Technology, China University of Petroleum (East China), Qingdao 266555, China
2. Department of Chemical Engineering, University of...
Shale gas reservoirs are typically characterized by nanometer pore throats and very low permeability matrix requiring hydraulic fracturing stimulation of horizontal wells. Water is the main fluid used in hydraulic fracturing and a variety of chemicals are mixed with the water each for a different pur¬pose. Given the very low permeability of shales, very high pressure gradients are experienced...
Poultice technology is currently mainly used for the desalination of masonry structures in the field of architectural heritage conservation [1]. Wet poultices are coated on the porous material to be treated, and kept in place before being removed when dry. The efficiency of the process basically depends on the drying behavior of the system poultice/substrate, but so far little is known...
After production, all wells need to be permanently plugged and abandoned (P&A'ed). Long-term well integrity will then rely on the integrity of cement, which is the material typically used for permanent well plugging and for filling the annular spaces between casing/rock. The cement is pumped into the well as a slurry, and hardens to form mechanical and hydraulic seals. Cement has proven to be...
As a kind of clean and potential energy resource, large quantities of gas hydrates have been proved to exist widely in the permafrost and in deep marine environments with high pressure and low temperature conditions favorable for their formation. Recently, how to develop and exploit the natural gas hydrate reservoir efficiently is one of the critical issues in the energy resource R&D in 21st...
Microbially Induced Calcite Precipitation (MICP), or bio-cementation, has shown significant promise as an environmentally-conscious alternative to traditional geotechnical ground improvement technologies, which oftentimes rely on hazardous grouting chemicals, high mechanical energy, and energy-intensive materials to improve the engineering properties of soils (DeJong et al. 2013). In the urea...
Foam fluid is a gas-liquid dispersion system whose range of application covers various fields due to its excellent properties, especially in oil and gas field development including enhanced oil recovery, matrix acidizing, gas breakthrough control, profile control, plugging removal, etc. However, factors such as dependence on natural N2 sources, breakthrough of N2 to production wells,...
Natural Gas Hydrate (NGH) widely distributed in marine sediments and permafrost areas has attracted global attentions as potential energy resources. Permeability is a critical parameter that influences the gas production potential from hydrate reservoirs. The hydrate saturation affects the characteristics of the porous media, which is also the key factor determining the permeability. In this...
Biologically mediated processes are being developed as an alternative approach to traditional ground improvement techniques. Denitrification has been investigated as a potential ground improvement process towards liquefaction hazard mitigation. During denitrification, microorganisms reduce nitrate to dinitrogen gas and facilitate calcium carbonate precipitation as a by-product under adequate...
In a geological carbon storage (GCS) project, it is critical to predict the extent of injected CO2. However, it is not practical to quantify the uncertainty in the CO2 plume extent by conducting full physics flow simulations for hundreds of geological models representing high geological uncertainty. In this study, a computationally efficient surrogate model is introduced to quickly approximate...
In areas contaminated by the petroleum industry, persistent compounds such as polyaromatic hydrocarbons (PAH) are often accumulated in the porous matrixes of sediments and soils (S&S), implicating risks to ecosystems and human health since these contaminants are released over time to interstitial and surrounding water. Pore size distributions (PSD) and PAH binding strengths to sorption sites...
Modeling DNAPL source zone plume evolution using traditional flow and transport models is a computationally intensive process that requires specification of a large number of material properties and hydrologic/chemical parameters. Given its computational burden, Monte Carlo simulation using such models is particularly ill-suited for uncertainty assessment and/or subsurface sampling...
Hydraulic fracturing fluids (HFF’s) have been used for several decades to control mechanical, hydraulic, and geochemical behavior in unconventional reservoirs during stimulation. The interactions that occur in these environments during stimulation (hydrofracturing) are designed to prevent scaling, improve production, and prevent damage to formations. However, there is still uncertainty with...
A multi-relaxation-time lattice Boltzmann (LB) model for nanoscale liquid flow is developed to investigate the liquid flow characteristics in nanoporous media. The slip length and effective viscosity obtained from molecular dynamics (MD) simulations are adopted to account for the nanoscale effect. First, the LB model for water flow in nanopores is built and water flow characteristics in...
Hot solvent injection is an in-situ technology which uses heated solvent for efficient and sustainable viscous oil (VO) recovery (cf. 93 kg per barrel less GHG emission than SAGD technology). The process reduces the oil viscosity via mass and heat transfer so that the combined effect of heating and solvent dilution yields a better result than in steam (SAGD) or cold solvent injection (VAPEX)...
Heat conduction in granular porous media is a phenomenon that is relevant to a broad spectrum of problems in science and engineering disciplines including physical, earth, and biological sciences, to name a few. Effective thermal conductivity in granular porous media is a function of morphological features of the medium such as grain shape, grain size, and geometrical structure. Thermal...
The inverse problem of parameter identification consists in the optimal determination of model parameters using water-level observations. We are concerned with the estimation of the transmissivity and storativity in a confined aquifer in transient conditions. One of the approach used to solve this problem, is called the Differential System (DS) method. It is based on the solution of a Cauchy...
Flows in packed beds are encountered in many engineering applications, such as solar thermal energy storages, chemical catalytic reactors, petroleum and civil engineering, magnetic refrigerators, biological tissues, and pebble-bed nuclear reactors.
Critical challenge of designing packed beds involves understanding the total pressure loss, complex flow fields, heat and mass transfer phenomena...
Proppants are small, granular additives used in hydraulic fracturing to keep induced fractures open and permeable after the reservoir pressure is lowered; typically sand is used. These materials are designed to resist the closure force across a fracture face and allow fluid to migrate out of the system. While the simple mechanical support of the proppant keeping a fracture open is well...
Natural gas hydrate is an ice like crystalline compound with a cage structure under high pressure and low temperature. The hydrate will decompose when the pressure is lower than the hydrate equilibrium pressure, so the pressure propagation rule is different from the porous medium without hydrate. Based on the theoretical analysis method of fluid mechanics in porous medium and considering the...
Shale rocks play an essential role in petroleum exploration and production because they can occur either as caprocks for subsurface storage in conventional reservoirs or as unconventional reservoir rocks for hydrocarbon extraction via hydraulic fracturing. The ability to produce gas from rocks previously only considered caprocks is an unprecedented and innovative feat, but does not come...
In order for a deep-water wellbore to uphold its integrity under high pressure - high temperature conditions, the wellbore must possess complete zonal isolation while surrounded in an extreme environment. Highly variable temperature and pressure ranges, shallow flow zones, as well as potentially corrosive fluids and gasses all present unique challenges to the job of the cement which maintains...
Objectives/Scope:
Foam can improve sweep efficiency in gas-injection enhanced oil recovery. Surfactant-alternating-gas (SAG) is a favored method of foam injection due to injectivity and operational considerations. Laboratory data indicate that foam can be non-Newtonian in the high-quality regime, and therefore during gas injection in a SAG process. We investigate the implications of this...
The effective visco-elastic properties of reservoir rocks are strongly dependent on characteristics of the pore geometry and of the inherent viscous pore fluids, saturation degree and excitation frequency. Constraining these dependencies is important for the interpretation of seismic data from geothermal or oil and gas reservoirs. Thus, experimental studies are needed that focus on effective...
The Center for Biofilm Engineering (CBE) at Montana State University has a long, successful history of investigating biofilm and mineral precipitation processes in subsurface environments. This poster summarizes many of the experimental approaches the CBE has taken to develop field-suitable technologies. There are numerous applications for engineered biomineralization. The CBE has largely...
Pore structure of large scale porous limestone reservoir with strong heterogeneity is very complex，so it is difficult to evaluate its pore structure of Mishrif Formation of W oilfield in Iraq. Based on thin section observation，porosity and permeability test and mercury injection capillary pressure test，fractal theory was applied to quantitative pore structure evaluation，and the pore fractal...
We present a theoretical investigation on the processes underpinning the reduced longitudinal spreading documented in stable variable density flows, as opposed to constant density settings, within heterogeneous porous media. We do so by decomposing velocity and pressure in terms of stationary and dynamic components. The former corresponds to the solution of the constant density flow problem,...
Injection of supercritical carbon dioxide (CO2) into geological formations is used for both atmospheric greenhouse gas reduction (climate change mitigation) and enhanced oil recovery. In an effort to fully understand CO2 trapping efficiency, the capillary trapping behaviors that immobilize subsurface fluids were analyzed at the pore-scale using pairs of proxy fluids representing the range of...
To quantify in-situ CO2 residual trapping for CO2 geological storage, dedicated push-pull experiments have been carried out at the Heletz, Israel pilot CO2 injection site. The site is well characterized and instrumented for CO2 injection and sophisticated sampling and monitoring (Niemi et al., 2016) and residual trapping experiments have been carried out during 2016-2017. The objective of the...
To date, soil bio-cementation via Microbially Induced Carbonate Precipitation (MICP) has been extensively studied as a promising alternative technique for ground improvement to address the growing environmental concerns of traditional chemical cementing agents. This paper presents a new one-phase injection method of biocementation using an acidified all-in-one biocementation solution (i.e., a...
We present a numerical analysis of fluid phase distributions and relative permeabilities obtained from direct pore-scale simulations of two-phase flow through a real pore space with diverse conditions of wettability. Exploring the effects of wettability on the fluid behaviors within porous media is of fundamental relevance for a variety of engineering as well as environmental applications,...
Fractal model of gas diffusion coefficient is derived for porous nanofibers, which are assumed to be composed of a bundle of tortuous capillaries whose pore size distribution and roughness of wall surfaces of capillaries follow the fractal scaling laws. The analytical expression for gas relative diffusion coefficient is a function of the relative roughness, fiber radius and microstructural...
3d printing in the oil and gas industry is in its infancy. The ability to use 3d printing to not only produce tools and equipment, that could not be manufactured in traditional manners, is only the beginning. There are several possible applications for 3d printing to facilitate this project:
• Controlled deposition of unique and varied barrier materials
• Equipment development for...
Most of the water-flooding fields in the eastern part of our country have now entered the stage of high-water-cut mining, their actual recovery rates are generally low. Because of this, the research on the remaining oil distribution in the reservoir is urgent. In order to reflect the influence of the pore structure parameters of the core on remaining oil from the microscopic scale, this...
Foam injection into the subsurface is generally performed to improve gas mobility control during enhanced-oil recovery (EOR) and contaminated site remediation (Lake et al., 1989; Hirasaki et al., 2000; Mulligan et al., 2006). Several experiments have been conducted to study the foam generation mechanism at both the pore and continuum scales (Kovscek et al., 1994; Kam et al., 2003; Gauteplass...
Geomaterial pore networks are highly tortuous with intricate geometries and varying surface roughness. It is reported in literature that both pore geometry and surface roughness influence flow through porous media (Ketcham and Carlson, 2001; Noiriel et al., 2016; Lv et al., 2017). Surface roughness is quantified by the deviations in the direction of flow perpendicular to the real surface....
Although foams are known for effectively reducing gas mobility and enhancing oil recovery in many field applications, it is still not clear how far the injected fine-textured foams will propagate into the reservoirs. Lacking such a knowledge makes the design of foam field treatments difficult and often unreliable. The purpose of this study is to investigate CO2 foam propagation distance as a...
Flow and transport in porous media is encountered in many industrial and hydrogeological applications, such as hydrogen fuel cells, inkjet printing, hydrocarbon exploration, and subsurface remediation. The relevant study domain can cross multiple scales from a few nanometers to hundreds of kilometers. Therefore, in porous media research, the upscaling and multiscale techniques have been widely...
Soil is a complex environment in which the presence of several phases creates numerous interfaces (solid-liquid, liquid-gas and solid-gas). Understanding the local hydrodynamics in soil pores and the biogeochemical processes such as nutrient cycling has been of growing importance in the field of bioremediation and ecology. Besides the coexistence of two immiscible phases (air and water) in the...
Zhang Yongfeng, Jiang Yongxu, Lu Guoqiang
Exploration and Development Research Institute of Daqing Oilfield Company Ltd.,Daqing,China
ABSTRACT: This papers identity the coal structure in Daqing exploration area, and to discuss types of pore in different basins. Coal is a complicated porous medium. Adsorbability and permeability of its pore structure for coalbed methane (CBM) has drawn...
Understanding the influence of CO2 injection on rock stress is one of the key elements to analyze CO2 Enhanced gas recovery and long term CO2-storage in tight sand gas reservoirs. Producing natural gas from reservoir and injecting CO2 to the tight reservoir causes a change in pore pressure, which in turn, changes the three dimensional effective stress state. The stress path followed by the...
Salt are a major cause of destruction by crystallization of porous media. Salt will in general enter a porous medium by advection with moisture or diffusion within the moisture. A special situation which occurs often in marine environments in which case there is a permanent supply of sea water at one side of a porous material such as a concrete structure. At the other side, the structure is...
Microbial dynamics in porous media are drivers for a number of applications in subsurface pollutant remediation. Biofilms are communities of microorganisms that are attached to interfaces (pores-grains), and embedded within a matrix of extracellular polymeric substances (EPS) that they have produced. Growing biofilms have a very small effect on porosity, but a very significant effect on the...
To understand how does the injected CO2 migration could help increase the available storage capacity in geologic formations, this paper reports a series of experiments of core flooding. To examine the effects of CO2migration pathways in geologic formations, our team have developed a core flooding test of displacing water in porous media with CO2. The samples were obtained from the Ordos Basin,...
Dual-porosity media widely exist in natural reservoirs and have been received much attention in heat and mass transfer. Due to multiplicative cascade effects, the microstructure might be disordered and complicated, with fractures/pores scale-invariantly distributed. In this study, we briefly introduce the concept of General Fractal Topography proposed recently which not only reduces modeling...
Fluid flow though geologic fractured/porous media tends to become non-Dacian as a result of the competition between viscous and inertial forces and the effect of pore geometry variation. The Forchheimer equation has been widely shown to apply in these situations, in which the coefficient of viscous permeability (kv) is largely predictable, but this is not so for the coefficient of inertial...
We present here our efforts to characterize wellbore interfaces via chemical and mechanical characterization methods. These methods including mechanical “push-out” tests to measure interfacial bond strengths between cement, host media, and polymeric seal repair materials, 3D geochemical modelling of the wellbore environment during subsurface operations, and “mock-wellbore” experimental test...
In the context of geological carbon sequestration (GCS), carbon dioxide (CO2) is often injected into deep formations saturated with a brine that may contain dissolved light hydrocarbons such as methane (CH4). In this multicomponent multiphase displacement process, CO2 competes with CH4 in terms of dissolution, and CH4 tends to exsolve from the aqueous into a gaseous phase. Because CH4 has a...
• Akerke Mukhamediarova (Institut Elie Cartan, Université de Lorraine)
• Mikhail Panfilov (Institut Elie Cartan – Université de Lorraine ; and
Institut Jean le Rond d’Alembert, Sorbonne Universités)
Oil displacement by water which contains microorganisms able to produce bio-surfactants is one of the most promising methods of oil recovery. The bio-surfactant significantly reduces...
The progression of reactions in systems where mixing occurs has been the subject of investigation for decades; however, there is still much that is unknown about such systems. One area of particular interest to us is the influence of the initial configuration of a system as it evolves in time. Many (if not most) investigations of mixing are formulated at the long time limit, which requires...
The phenomena of tight gas reservoirs with super-normally saturated water, which exhibit the unique combination of very high initial water saturation combined with low to very low permeability (permeability of less than 0.1 mD) exist extensively in a number of regional sedimentary basins. Traditionally, multiphase flow of natural gas and connate water is evaluated in laboratory by conducting...
In EOR research, the use of natural reservoir core is faced with four main problems: 1. The repeatability of the petrophysical properties in natural reservoir core is poor, making it unsuitable for contrast and repeat experiments to examine the influence of individual petrophysical factor under specified physical conditions. 2. The physical properties of the natural reservoir core are...
Physics of two-phase flows in heterogeneous natural rocks plays an important role in many applications, such as carbon sequestration in deep saline reservoirs and recovery of oil from hydrocarbon reservoirs. Although pore-scale models are used to compute macroscopic average properties required in field-scale simulators, most work is limited to small sample size. There is a need for pore-scale...
Surfactants can drastically reduce the water/oil interfacial tension (IFT) to mobilize residual oil. However, surfactant flooding is viscously unstable inherently because of its large mobility ratio. Alkaline/surfactant/polymer (ASP) flooding has been serving as a conventional solution, where polymer plays a vital role in increasing viscosity for a more stable oil bank. Recently, a...
Density-driven convection can accelerate the rate of CO2 solubility trapping during geological CO2 storage in deep saline aquifers. We present a bench-scale experimental method based on refractive light transmission (RLT) in an analogue system that enables comprehensive study of solutally induced density-driven convection in saturated porous media. In an analogue system, we investigate...
Subsurface flow processes involving non-Newtonian fluids play a major role in many engineering applications, from in-situ remediation to enhanced oil recovery. The fluids of interest in such applications (f.e., polymers in remediation) often present shear-thinning properties, i.e., their viscosity decreases as a function of the local shear rate. We investigate how fracture wall roughness...
Cold Heavy Oil Production with Sand (CHOPS) is widely used as a primary non-thermal production technique in thin heavy oil reservoirs. Development of the complex wormhole networks (i.e., high-permeability channels caused by sand production) renders the scalability of post-CHOPS solvent-aided processes to field applications challenging. It is widely accepted that configuration of wormhole...
As length scales grow smaller, the behavior of two fluids flowing through a porous media is more and more strongly affected by capillary pressure. The canonical Young-Laplace equation gives a good estimate of the pressure change across fluid interfaces, but it is technically valid only in equilibrium conditions. It is well-known that for two fluids flowing in capillaries, the interfacial...
The goal of this study is to optimize a dual-fiber filter media by increasing the dust holding capacity (DHC), while maintaining the initial pressure drop and initial filter efficiency. Three main parameters define the performance of a filter, namely the DHC, filter efficiency and pressure drop. The DHC defines the quantity of solid particles which a filter media can trap and hold before the...
From Images to Rock Properties
In the Oil and Gas industry, digital images of rock samples are being collected and utilized for reservoir formation characterization more frequently than ever. This is in part due to the fact that imaging tools such as X-ray CT scanners and SEM’s have become more prevalent, and also due to the challenges and time-consuming processes in traditional core analysis...
Target formations for large-scale CO2 sequestration are often saturated with brines that contain dissolved methane and other light hydrocarbons. When CO2 is injected in such deep formation, non-trivial phase behavior may result in methane exsolving from the brine and forming a free gas phase. Because methane has a lower viscosity than the (generally supercritical) CO2, this methane-rich gas is...
We propose a novel finite volume method for anisotropic linear elasticity problem. The derivation of the flux approximation method for elasticity problem closely follows our previous work [1] on the nonlinear finite volume methods for diffusion equation featuring positivity and discrete maximum principles. It is based on the extensions of the harmonic point idea of [2] from the scalar to...
Non-uniform fluid displacements in heterogeneous porous media are commonly observed, while are unfavorable in oil/gas recovery processes. Recently, the deformable polymer particle gels such as preformed particle gel (PPG) [1] and soft micro-gel (SMG) [2] were successfully applied to improve the sweep efficiency under such bad conditions. Although experimental studies presented qualitative...
We develop higher order multipoint flux mixed finite element (MFMFE) methods for solving elliptic problems on quadrilateral and hexahedral grids that reduce to cell-based pressure systems. The methods are based on a new family of mixed finite elements, which are enhanced Raviart-Thomas spaces with bubbles that are curls of specially chosen polynomials. The velocity degrees of freedom of the...
Reverse Osmosis Membrane (ROM) filtration systems are widely utilized in waste-water recovery, seawater desalination, landfill water treatment, etc. During filtration, the system performance is dramatically affected by membrane fouling which causes a significant decrease in permeate flux as well as an increase in the energy input required to operate the system. Design and optimization of ROM...
Three-dimensional (3D) analyses of the pore structure of building materials are becoming progressively more important in recent years in order to get more accurate interpretations and simulations of moisture and heat transfer properties. These characteristics are a major determinant for the durability and sustainability of structures as well as for the health and comfort of the building...
Solid nanoparticles (NPs) have shown promise to play a major role in novel enhanced oil recovery methods by altering reservoir wettability, reducing interfacial tension and increasing mobility ratio. Solid nanoparticles could be implemented as emulsion stabilizing agents in combination with surfactants and polymers. Stabilized emulsions are a desired state in enhanced oil recovery. In this...
Accurate modeling and robust computation of the phase behavior is essential for optimal design and cost-effective operations in petroleum reservoirs as well as in petroleum processing plants, where we need to understand the fluid flow of partially miscible multi-component multi-phase mixture in free spaces or in porous media. Phase behavior calculation of fluid mixture consists of stability...
Self-assembly of surfactants in confined geometries plays an important role in environmental, chemical and pharmaceutical technology. Adsorption of surfactants at metal oxide and other polar/charged surfaces depends primarily on the nature of their head groups: cationic surfactants exhibit high-affinity adsorption due to the interaction of the positively charged head groups with negative...
Water is the most predominant component in steam injection processes, such as steam-assisted gravity drainage (SAGD). The main hypothesis in this research is that in-situ oil transport can be substantially enhanced by generating oil-in-water emulsion, where the water-continuous phase acts as an effective oil carrier. The objective of this paper is to evaluate the capability of oil-in-water...
Wettability of porous media has a remarkable influence on the morphology of invading fronts during fluid-fluid displacement. For example, it has been shown that when invading and defending fluids exhibit an instability-inducing viscosity ratio, the invading phase advances through viscous fingering, and the width of the fingers is dictated by the substrate wettability. When the porous medium...
Barometric pressure variations are often one of the main drivers of gas transport in fractured rock, a process that is referred to as barometric pumping. Barometric pressure variations are complex, multi-frequency signals influenced by latitude, weather, elevation, lunar phase, time of year, and diurnal and semi-diurnal earth tides. However, our results indicate that it is often a subset of...
In order to improve the performance of the exhaust after treatment system and keep reasonable complexity, the number of the used devices is reduced by enhancing wall flow particulate filters with a catalytic functionality, like selective catalytic reduction in diesel or three way catalysis in gasoline vehicles. In this case the solid matrix of the filtering media consists from inert grains and...
In this work a general model of multiphase flow and multicomponent transport in porous media to simulate, analyze and interpret hydrocarbon recovery processes by injecting low salinity water using open source software is presented. The flow model is multiphase considering capillary pressure and relative permeabilities depending on salinity, while the transport model is multicomponent and...
An important and largely unsolved problem is accurate prediction of the onset of precipitation of heavy organic compounds, such as asphalts, on the surface of the pores of a porous medium, such as oil reservoir. It was suggested some time ago that an effective method of identifying the onset may be through measuring the electrical conductivity of the solution that contains the heavy organic...
Extracting structural information, such as pore networks, from tomographic images is a powerful tool for the study of porous materials. Pore network models are used for predicting different physical properties such as permeability and tortuosity, and simulating chemical process such as reactive transport. Due to its inherent simplifications, pore network modelling requires far less...
The confinement of liquids in porous media greatly influences their physical properties, in particular, when the pore size approaches the molecular length scale. Several mechanisms, such as the pure geometrical restriction and the liquid-solid interaction at the interface contribute to the confinement effects, however, their roles for the drastic changes in the thermodynamic and dynamic...
This work provides a comprehensive study to evaluate and optimize the effectiveness of nanofluids to both prevent fines migration and enhance oil recovery using different utilization approaches: nanofluids co-injection and pre-flush. To do that, 1) a comprehensive review of both laboratory experiments and field cases is adopted to confirm the effectiveness of nanoparticles to control fines...
Calcium carbonate (CaCO3) precipitation is a frequently-occurring natural subsurface process, in which supersaturated CaCO3 in brine can precipitate in subsurface environments. This phenomenon can naturally occur as part of diagenesis of rocks and can also be utilized for soil improvement. This study explored abiotic carbonate precipitation in coarse sands using X-ray microtomography (X-ray...
At the nanoscale the positions of coexistence lines on the phase diagrams are shifted and their new locations depend mainly on the size and shape of the nano-confinement, the structure of the confining walls, and their interaction with the confined substance. Here we show that it is possible to induce structural transformations in a confined system by simply varying the number of molecules...
We present a major new advance in the interpretation of percolation characteristics, provided by mercury porosimetry, porometry, water retention for soils, and, for nanoscale porosity, Grand Canonical Monte Carlo simulations matched to surface area adsorption measurements. The new method provides a complete analysis of all the void types, providing the user with cumulative distributions that...
In this presentation, we explore applications of the maximal inscribed sphere (MIS) map to characterize porous media and show connections with other laboratory measurements. Three-dimensional maps can be computed from x-ray micro-tomography images of porous rocks and have been commonly used to simulate mercury injection capillary pressure (MICP) curves. We present additional applications of...
In this work, we study the efficiency of the filter media at different operational regimes. In particular, we focus on how the media microstructure influences the efficiency performance, which is quantified by macroscopic parameters. We investigate the microscale characteristics since the filtration is an intrinsically multiscale process. On one hand, contaminant adsorption onto the fibre...
Steam assisted gravity drainage (SAGD) is the main technologically and economically feasible method for in situ bitumen extraction. While SAGD is effective, the steam generation process is a major source of CO2 emissions, and many strategies are currently under test to improve both the environmental and economic performance. Solvent-based processes – either pure solvent injection or...
Low salinity water flooding is an effective and cost-efficient improved oil recovery method. Wettability alteration is believed by many to be the primary reason for the observations of increased recovery. However, the causes of the wettability alterations and approaches for optimization are not fully understood. We conduct experiments in micromodels by injecting brine at different salinities...
A deep geologic repository (DGR) for low- and intermediate-level radioactive waste has been proposed at the Bruce nuclear complex on the eastern flank of the Michigan Basin in southeastern Ontario, Canada. The proposed location for the repository is at a depth of ~680 m, in the middle of a ~450 m-thick sequence of Ordovician-aged shale and limestone with extremely low porosity and...
CO$_2$ capture and storage is an important technology for mitigating climate change. Design of efficient strategies for safe, long-term storage requires the capability to efficiently simulate processes taking place on very different temporal and spatial scales. The physical laws describing CO$_2$ storage are the same as for hydrocarbon recovery, but the characteristic spatial and temporal...
Polymer-electrolyte fuel cell (PEFC) is a promising energy conversion technology with high thermodynamic efficiency, power density and zero-emission. Due to their low cost and material abundancy, PGM-free electrodes are promising candidates for meeting 2020 cost targets set by U.S. Department of Energy (DOE) [1]. However, to compensate the lower volume-specific activity, these catalyst layers...
In this work, we investigate CO2 exsolution, transport, trapping and dissolution in shallow subsurface under various conditions.
First, we introduce mathematical model describing the system. For the mass transfer of CO2 the rate limited model is used.
Numerical results obtained using the model are compared to the experimental data obtained from two sets of experiments: 1D column experiments...
Fractures should be simulated accurately given their significant effects on whole flow patterns in porous media. But such high-resolution simulation imposes severe computational challenges to numerical methods in the applications. Therefore, the demand for accurate and efficient technique is widely increasing. A near-linear complexity multiresolution decomposition is proposed for solving flow...
Unlike macroscopic objects, any system of nanometric size shows characteristics that strongly depend on its size and geometric form. It is the consequence of the fact that the major part of atoms (or molecules) of nano-object is located at its surface, their cohesive energy is smaller than for the atoms in the bulk.
Here we show that when a fluid is confined in nano-volume, delimited by...
This contribution deals with numerical simulations of immiscible two-phase flow in heterogeneous porous media. The hydrodynamic properties of the geological porous media are naturally discontinuous at the Darcy scale, which has to be accounted for by discretization methods. In this talk we focus on handling extreme heterogeneities in the capillary pressure/saturation relation arising, in...
Multiphase flow in porous media is important in many natural and industrial processes, including geologic CO2 sequestration, enhanced oil recovery, and water infiltration into soil. Although it is well known that the wetting properties of porous media can vary drastically depending on the type of media and pore fluids, certain aspects of wettability control on multiphase flow continue to...
In this work we consider a mixed finite element formulation using the enhanced velocity (EV) method to construct a strongly flux-continuous velocity approximation on spatially non-conforming grids. The EV method was recently generalized to semi-structured grids, in which each subdomain represents its own mesh refinement level of a structured grid with arbitrary inactive cells. The union of...
Reactive transport modelling at the pore scale explores the spatial-temporal changes in the pore network geometry, the flow field and water composition at sub-centimetre scale. It requires a true representation of fluid-mineral boundaries and their role as zones of fluid-mineral reactions, spatially explicit mass transport and a set of chemical equations to calculate the aqueous speciation and...
Mudrocks are the dominant rocks in the Earth crust and are as well noted for their heterogeneity at several orders magnitude of scales. This implies a significant challenge in relating observations at varying scales to one another. A unique attribute that controls petrophysical properties of mudrocks is their microstructure which also controls fluid movement within them. Due to the...
Clay minerals are ubiquitous in the subsurface: they are found in CO2 sequestration targets (e.g., sandstones) and in the seals above them, and are major constituents of unconventional shale plays considered for natural gas recovery. A significant fraction of the porosity in clay-rich systems is occupied by micro- and meso-pores that provide a large surface area for physical and chemical...
Soil moisture is closely linked to the near-surface heat and mass transfer that couples the land and atmospheric states. The accurate simulation of the spatiotemporal distribution of soil moisture is constrained by existing knowledge gaps with respect to the mechanisms and processes linking the atmospheric and soil states, their magnitude, and sensitivity to applied soil conditions. In this...
Containment of injected CO2 is of prime importance for long term integrity of CO2 geological storage projects. Structural/stratigraphic, dissolution, residual, capillary and mineral trapping mechanisms play significant roles on different time scales to keep the injected CO2 within the storage zone boundaries. In heterogeneous media the impact of capillary trapping mechanism becomes...
Fluid flow in porous media occurs on varied scales from pore to reservoir, where the fine scale heterogeneity may have a significant impact on large scale fluid flow. Resolving all pertinent scales in modeling and flow simulation is an arduous task limited by the availability of data and computational resources. Therefore, it is customary to use an upscaling procedure, in which the fine scale...
It is proposed in this talk to consider multiple resolution observations of dentine materials synthetized at multiple scales with a general inverse problem approach by combining confocal e.g. with SEM observations at different scales. Thus correlative microscopy aims to access a large range of scales for a given region by combining what is impossible by using one instrument alone.
Dentin is...
Compositional variation in multi-component system caused by adsorption and confinement in organic nanopores leads to capillary condensation and trapping of concentric hydrocarbon liquids. The objective of this paper is to show the presence of capillary condensation in kerogen pores, and argue that pressure depletion/fluid expansion is no longer effective and EOR process is required for these...
This work develops the theoretical basis and practical application of a promising class of safeguarding strategy in the context of the solution of implicit timesteps for multiphase multicomponent flows in general.
While classic globalization methods such as the linesearch for sufficient descent are problem independent, they require numerous computationally costly evaluations of the...
Dissolution phenomena in porous media play an important role in the transport of sequestered CO2. Petrophysical properties can be dramatically altered by resulting pore structural changes, including the formation of high conductivity channels, known as “wormholes”. As it is difficult to forecast the emergence of wormholes based on experimental information, it is of vital importance to be able...
Flow and transport processes in fractured rock are strongly influenced by fracture aperture and diffusive interactions between the fractures and rock matrix. The transmissivity of fractures is highly sensitive to fracture aperture (a cubic dependence). Complex thermo-hydrologic-mechanical-chemical (T-H-M-C) coupled processes that alter fracture apertures thus drive feedbacks and pattern...
We present general formulations of the phase-equilibrium and phase-stability problems for multicomponent mixtures and verify that these formulations generalize the problems of phase-equilibrium and phase-stability at constant volume, temperature, and mole numbers ($VTN$-flash), at constant internal energy, volume, and mole numbers ($UVN$-flash), and at constant pressure, temperature, and mole...
OBJECTIVES/SCOPE:
Existing rarefied gas flow models cannot accurately unify various flow mechanisms by empirical methods and overlook the van der Waals effect. In this paper, a model for non-ideal rarefied gas flow in nano- and micro-porous media is developed based on the well-recognized Bravo’s conceptual layered model with the rigorous interpretation. The gas transport behavior in nanopores...
In this work, we develop and analyze an adaptive multiscale approach for Stokes problems in heterogeneous perforated domains. In many applications, these problems have a multiscale nature arising because of the perforations, their geometries, the sizes of the perforations, and configurations. Typical modeling approaches extract average properties in each coarse region, that encapsulate many...
In many subsurface energy activities, such as hydraulic fracturing, geologic carbon storage, deep well disposal, and geothermal energy, the injection or extraction of fluids results in significant mechanical and chemical perturbations. These perturbations pose risks in promoting unwanted fluid leakage pathways, such as faults and fractures, through chemical reactions and mechanical failure....
Emissions of methane and other hydrocarbons from old or abandoned oil and gas wells are a growing environmental and public safety risk. There is growing interest in identifying materials that are inexpensive and can be easily pumped into the wellbore from above in order to create a permanent seal for leaking hydrocarbons. Here we developed a novel bio-clay composite (BCC) material with the...
Although two-phase flow in porous media is an established research field since decades, its theoretical background is still incomplete. In particular, while a universal definition of capillary pressure exists at the micro-scale, its upscaling to the macro-scale is still rather vague and a rigorous theory of capillarity at the macro-scale is missing. In this work, a new macroscopic theory of...
Hydraulic fracturing is one of primary engineering techniques to improve well productivity especially for unconventional reservoirs. Generally, there are two kinds of numerical models for hydraulic fracture simulation, continuum-based models and discontinuum-based models. In continuum-based models governing equations based on continuum theory are solved with single planar fracture assumption....
Modelling multiphase porous media flows is important in many engineering areas such as geothermal energy extraction, unconfined aquifers, CO2 storage, magma reservoirs and hydrocarbon reservoirs. However, modelling of multiphase porous media flow is very challenging due to various reasons: the relative permeabilities (controlled by the saturation) introduces high non-linearities in the system;...
Multiphase multispecies transport is an essential field of studies for a wide range of engineering applications including acid gas treatment, waste water management and bubble column reactor. In particular, pore-scale investigations of subsurface processes have recently attracted a lot of attention in many domains such as oil and gas production, CO2 storage and contaminant hydrology. On the...
Production from tight oil reservoirs is challenging mainly due to low rock permeability and the resulting rapid decline in well production performance, specifically when the pressure drops to below the bubble point. Currently, there are several pilot tests focusing on different enhanced oil recovery (EOR) strategies to improve the recovery performance in these reservoirs. Specially in Canada,...
In reservoir simulation, solving highly nonlinear algebraic equations arising from a fully-implicit discretization is challenging. There is generally no acceptable initial iterate available for multiphase flow and transport problems. Hence, a globalization strategy is usually needed when applying Newton's method to the nonlinear system.
Homotopy continuation, which has been widely adopted...
This presentation report recent advances in the framework of the discrete element method (DEM) for multiphase granular media. Computationally efficient methods based on the DEM have been developed for a while for partially saturated materials but they have been generally limited to the pendular regime. In contrast, one hardly avoid expensive direct resolutions of 2-phase fluid dynamics problem...
Geologic Carbon Storage is one method available to mitigate excess carbon dioxide produced at point sources. X-Ray micro-computed tomography provides the resolution requirements necessary to image in situ contact angles (θ) at representative conditions; however, experimental data is limited and varies among materials and temperature settings used in literature (Andrew et al., 2014, Lv et al.,...
Dissolution within porous media is a critical process in many environmental and geological settings. The formation and evolution of soils, rocks, and landscapes (Buhmann and Dreybrodt, 1985; Brantley, 2008; Jin et al., 2010), efficiency of carbon capture in geological reservoirs (Matter and Kelemen, 2009), and the weathering of man-made structures are all highly dependent on the rates at which...
Thermal oil recovery methods have been proposed and progressed for many years as a convenient way to mainly unlock the potential from heavy oil/bitumen accumulations. These methods cover a wide range of techniques like steam/hot fluids injection, in-situ heaters, in-situ combustion, toe to heel air injection etc. A few of them are successful commercially while others are still under...
The Ganges–Brahmaputra Delta is a global hotspot for arsenic groundwater contamination.
Naturally occurring arsenic concentrates in water drawn from deep wells, creating a major
public health issue in West Bengal and Bangladesh that has been described as the largest mass
poisoning of a population in history.
A novel technology has recently been discovered that uses naturally abundant...
To decrease the atmospheric concentration of CO2, sequestration techniques whereby this greenhouse gas is injected in saline aquifers present in soils are considered. Upon contact with the aquifer, the CO2 can dissolve in it and subsequently be mineralized via reactions with minerals like carbonates for instance. We investigate experimentally the influence of such reactions on the convective...
Recent advances in three-dimensional imaging, using X-ray micro-tomography (µCT), has allowed to observe fluid configurations in porous media and measure various pore-scale properties such as contact angle, curvature, fluid connectivity (1-6). In general, gray-scale images obtained from µCT are pre-processed to remove artefacts before reconstruction and then filtered to enhance signal-to-noise...
Counter-current spontaneous imbibition (SI) is an important transfer mechanism that exchanges fluids between the mobile fractures and immobile rock matrix in naturally fractured reservoirs. The current state of the art of modelling SI involves the use of quasi-analytic solutions for symmetric imbibition along a 1D axis. Unlike contemporary simulators which use first order transfer functions...
Water transfers through wood structure play a major role in wood behavior under various conditions such as drying, imbibition, sapflow, for which various problems may occur, such as shrinkage, cavitation, fracture, swelling. The physical understanding of these transfers is in some cases rather poor, as illustrated by the fact that it is still sometimes considered that the permeability of wood...
Column tests are a widely use experimental tool to investigate particle transport in porous media. However, different experiments can produce similar breakthrough curves, which make these data insufficient in order to understand the governing processes that control particle transport under different conditions. Profile analysis of the deposited particles provides information about the particle...
During water flooding of viscous oil reservoirs, adverse mobility ratio leads to an unstable displacement and thus viscous fingering. Previous research in viscous fingering has focused on low flow rates and high permeability systems (above 1 Darcy). This paper provides a more thorough and systematic study of the factors affecting viscous fingering including lower permeability, different...
Many natural phenomena in geophysics and hydrogeology involve the flow of non-Newtonian fluids through natural rough-walled fractures and unconsolidated granular porous media. Therefore, there is considerable interest in predicting the pressure drop generated by complex flow in these media under a given set of boundary conditions. However, this task is markedly more challenging than the...
We are missing a deep understanding of the coupling of multiphase flows and fluid-solid reactions, including rock dissolution and mineral precipitation. To achieve this objective, we designed a geo-material microfluidic cell using limestone from SACROC unit (Texas, US) as substrate. For the single flow experiment, supercritical (sc) CO$_2$ dissolved in brine was flowed through a controlled...
A key element in digital rock physics is the segmentation of µ-CT scanned grayscale images into their constituent components, i.e. rock and pore. In this work, a multistep approach of segmentation is presented where the high degree of correlation present in neighboring voxels is utilized. The first step in the workflow is a modified fuzzy c-means algorithm which incorporates spatial...
Pore structure characterization and pore fluid assessment play an essential role in unconventional shale gas evaluation. However, the determination of petrophysical parameters, especially effective porosity for shale is challenging due to the impact of clay bound water (CBW), the tight texture and the complicated pore structure. In particular, no such porosimetric technique is able to...
4D-µCT is an increasingly popular tool to study dynamic processes in situ, for example in material science and porous media studies. The technique allows to resolve changes in a material's microstructure over time and in three spatial dimensions. Typically, a sample is scanned continuously during a relevant time-span, corresponding to multiple sequential conventional µCT scans, which are...
Viscoelastic surfactant solutions have a wide range of applications across many industries. In oil and gas applications, they are often used as hydraulic fracturing or displacement fluids due to their low damage inside the porous media, and their ability to improve the displacement efficiency. Recently, the microscopic displacement efficiency has been related to the rheological behavior of the...
Surfaces may influence elastic and plastic properties of nanostructured materials. Nanoporous gold (npg), as one of the most suitable probes for such effects, was mechanically deformed in an electrochemical environment allowing in-situ modification, i.e. electric charging as well as electrosorption of ion species, while the mechanical loading took place. The change in stiffness in the regime...
Fluid-fluid immiscible displacement in fractured media plays an important role in various subsurface processes, including enhanced oil recovery and geological carbon sequestration. The displacement patterns range from viscous to capillary fingering to compact displacement owing to the competition between capillary and viscous forces. Although has been profoundly studied for porous media, the...
The Gibbs energy of nanocrystals increases with decreasing crystal size due to an increasing surface to volume ratio (A/V) resulting in a solubility increase and a melting temperature decrease of small crystals. In the case of pure phases, the melting temperature decrease may be approximately represented by the Gibbs–Thomson (GT) equation. However, the melt of a salt hydrate is not a pure...
Reservoir properties of sandstones are controlled by precipitation and dissolution reactions at the pore walls. Both, the formation and dissolution of cement minerals are responsible for the complex pattern formation of porosity and permeability in reservoir rocks.
At the scale of drilled core sections (plugs), experimental and analytical approaches utilize positron emission tomography (PET)...
In the present study, miscible displacements are investigated through nonlinear numerical simulations. A practical scenario with concentration-dependent diffusion and velocity-induced dispersion is considered, which is widely encountered in many areas involving flow and transport in subsurface porous media. Different with most of previous studies with a constant injection rate, the...
Over the last decade, the generation of organic porous (nano)materials with tunable pore sizes and desired functionalities has been the subject of increasing attention in materials science. Interest in such porous frameworks originates from the large variety of applications in which they are involved, e.g. size/shape-selective nanoreactors, monoliths for advanced chromatographic techniques,...
Numerical modeling has been an increasingly important approach for better understanding fluid flow and transport phenomena in organic-rich, nanoporous shale. However, deployment of numerical models in the context of nanoporous shale is challenging because of the multi-length-scale nature of the porosity in shale, where pore sizes can range between the nanoscale (~ $10^{-9}$ m) and microscale...
Vugs and fractures have significant impacts on the fluid flow paths through fractured and vuggy porous media. On the other hand, the presence of vugs and fractures also can significantly affect the geo-mechanical behavior of the porous media. How to quantify and analysis the accurate effects of the vugs and fractures on the hydro-mechanical behavior of the media is still an opening and...
Digital core analysis has become an additional tool to physical experimental analysis for multiphase flow experiments. Digital core analysis is fast and can give more insight into the details inside a rock. In digital core analysis different imaging technologies with different resolutions are employed to identify pores and textures scaled from millimeters to nanometers in a heterogeneous rock,...
Soft nanoporous matter encompasses man-made materials such as compliant porous solids, intrinsically porous polymers and organic membranes as well as natural materials such as wood, bamboo, cotton and other plant-derived materials. These materials can undergo significant deformation during water adsorption because of strong coupling between the adsorption and mechanical properties. In...
Making predictions about flow and transport in a porous medium requires knowledge of the heterogeneous properties of the porous medium such as permeability. Computational methods for inverse analysis are commonly used to infer these properties from quantities that are more readily observable (such as hydraulic head in a hydrologic context). We present a method for computational inverse...
Pattern formation is ubiquitous in many physical or chemical processes and has been at the center of attention for the past couple of decades. In many instances, interfacial instabilities play a central role in creating these patterns and controlling their spatiotemporal evolution. Perhaps one of the most well-known examples is the striking figures generated when a high-viscosity fluid is...
Nanoremediation is an innovative environmental nanotechnology aimed at reclaiming contaminated aquifers. It consists in the subsurface injection of a reactive colloidal suspension for the in-situ treatment of pollutants. The greatest challenges faced by engineers to advance nanoremediation are the effective delivery and the appropriate dosing of the nanoparticles into the subsoil. These are...
In enhanced oil recovery, foam is used for its inherent capability to act as a mobility control agent. Compared to conventional displacement fluids, such as surfactant and polymer solutions, foams contain up to about 95% less water, have tunable rheological characteristics, and leave behind less residue. However, foams are thermodynamically unstable, especially when exposed to hydrocarbons,...
Two-phase coupling free flow and porous flow are encountered in a wide range of environmental and engineering applications, and several kinds of numerical models with different interface conditions have been built for it. Capillary pressure curve was usually considered in most models using J-function, but the threshold pressure was usually ignored because it’s relatively small compared with...
We study the effect of a non-monotonic viscosity profile on miscible viscous fingering in porous media. This hydrodynamic instability is studied by coupling the continuity and Darcy equations with a convection-diffusion equation for solute concentration that determines the viscosity. A toy viscosity model composed of a sequence of transformation in a sine function is considered. Parametric...
With our Software GeoDict® [1] we are able to segment 3d scans, e.g. CT or FIB-SEM scans. This segmented data can then be analyzed using GeoDict's new modules GrainFind and PoreFind. In this talk, we introduce GeoDict and present the features of these two modules.
For each individual pore, PoreFind extracts an equivalent ellipsoid from the segmented data. From the equivalent ellipsoids, we...
The redox flow battery is a promising energy storage technology for mitigating the uncertainty of renewable energy sources and bringing us a step closer to integrating them with the current energy grid systems. However, they are a relatively new technology that are unproven and currently too expensive. Optimizing flow batteries is an active area of research since it can potentially reduce...
A profound change in transport behaviors in porous media occurs for nano- and micro-particles (herein called colloids) in the presence versus absence of repulsion between colloids and collectors (porous media grains). This change is indicated by extended tailing of low colloid concentrations during elution, which is absent or present when repulsion is absent or present, respectively. It also...
Image segmentation is a critical step in any digital rock workflow. The classification of voxels into phases representing grains, pores, and sub-resolution features affects all the subsequent quantitative analyses performed from the tomograms as well as numerical modeling of physical processes within pore and solid phases. Although it has been an active research field for many years,...
The thermal interactions of fluid-solid regions occurring at pore-level during non-isothermal flow in porous media is usually characterized by the thermal dispersion coefficient at the macroscale. Thermal dispersion coefficient represents the combined effect of thermal diffusion and mechanical convection on the dynamics of heat transport in a porous medium. Thermal diffusion is the transport...
Permeable and hyperporous surfaces are common in natural systems, such as fractured rocks. Flow and transport above such surfaces is significantly affected by the surface properties, e.g., matrix porosity and permeability. However, the relationship between such properties and macroscopic solute transport is largely unknown. We focus on mass transport in a two-dimensional fracture with...
Methane hydrate is a non-stoichiometric crystalline structure in which water molecules form hydrogen-bonded cages with methane molecules inside. Abundant methane hydrate resources are present on Earth, especially in various mineral porous media (e.g., clays, coal, shale, permafrost and sea-floor).[1] Understanding the dynamics and thermodynamics of methane hydrate confined in porous media has...
Foodborne illnesses involving fresh produce have been increasingly causing concerns around the world. Pathogenic bacteria can attach to and colonize the surfaces of fresh produce, leading to contamination and illness outbreaks. however, mechanistic interactions between produce surface properties (e.g. roughness, topography and hydrophobicity) and bacterial retention remain poorly understood....
A common assumption in recent molecular simulation based investigations of hydrocarbon transport in kerogen is that the latter behaves as a rigid matrix [1-4]. In other words, its porosity remains relatively constant and irrespective of temperature, lithostatic (or external) pressure or fluid (or adsorption) pressure. This implies that the matrix isolates the fluid from external pressure...
A large number of applications in science and engineering involve the flow of non-Newtonian fluids in naturally-occurring and synthetic porous media. Examples include flow processes that are related to enhanced oil recovery, underground waste disposal, and groundwater contamination. In the recent years, a growing number of studies have been dedicated to investigate a wide variety of...
The flow of multiple immiscible fluids at the pore scale is sensitive to local porosity fluctuations that can be measured as pore scale disorder. Our high fidelity direct numerical simulations of pore scale multiphase flow indicate that the degree of disorder governs the expression of viscous instability at the pore scale. Instability is suppressed when porosity is highly ordered even for...
Nanoscale roughness (NR) is a physical heterogeneity on all surfaces, whereas chemical heterogeneity (CH) may sometimes arise from spatial variability in charge (CH1), Hamaker constant (CH2), and contact angles (CH3). Expressions were developed to determine the mean interaction energy between a colloid and a solid-water interface, or another colloid, when both surfaces contain binary NR and...
Physical properties of rocks such as permeability, relatively permeability, and dispersion coefficient are of critical importance for prediction of subsurface flow and transport. Advances in microscopic imaging have made it possible to obtain the pore-scale microstructure of rock samples via SEM, TEM, or CT scan at low costs and fast turn-around time. Image-based reconstructions have also...
We have studied mechanism of hydrogen storage in CAU-1 and CAU-8 metal organic frameworks synthesized at Christian-Albrechts-University of Kiel, Germany [1], [2]. The structures of these compounds are built from aluminum polyhedra with fully coordinated metal ions. Using various types of organic linker molecules tunable structures with channels of different geometries, but very similar...
The importance of fracture flow and matrix diffusion was investigated in two different fractured geologies: limestone and clayey till. Natural- and forced-gradient tracer tests were designed and conducted to analyze the transport behavior in the two fractured media and to investigate the required model complexity for the simulation of solute transport. A discrete-fracture model was employed to...
Porous electrodes with high specific surface area have been efficiently applied to design miniaturized electro-devices such as bio-batteries, bio-captors, etc. Such electrodes may provide much higher electrical current than classical flat electrodes of the same macroscopic size [1]. In a previous work [4], a multi-scale model of diffusion and electrochemical reaction in porous electrodes has...
A phase diagram of methane+n-butane mixture is investigated by the means of molecular dynamics (MD) simulations. The system exhibits retrograde condensation behavior above 191 K in some range of methane molar fractions. A vapor-liquid equilibrium curve for mixtures is calculated with TraPPE-UA united-atom forcefield [1], TraPPE-EH [2] and OPLS-AA [3,4] all-atom forcefields. The forcefields...
Waves in chromatography are well known to the practitioners. Characteristics of these waves are strongly correlated to the nature of the adsorption isotherm. We model the displacement of a finite slice containing an adsorbed solute by a carrier liquid flow. We examine the nonlinear dynamics that emerge from the interactions of rarefaction, shock layer and/or viscous fingers (VF) in the finite...
The effect of sulfate concentration and salinity on wettability alteration and crude oil-brine viscoelastic interfacial properties at elevated temperature was investigated in this work. Evidence exists that oil recovery can be improved through management of rock-fluid and fluid-fluid interactions. The multicomponent interfacial dynamic response is complex function of brine composition and...
Commonly, studies on imbibition focus on porous matrices with bicontinuous morphology that contain spongy pore systems with neck-node morphologies. In this context, much attention has been paid to cooperative imbibition phenomena such as imbibition front broadening, viscous fingering, or avalanche-like relaxations of the imbibition fronts, which occur in systems of hydraulically coupled pores....
Gas separation processes involving adsorption may have advantages over other separation methods although one drawback still remains the need for increased selectivity. A simple way to improve the selectivity of a separation process is to increase the pore confinement in the adsorbent. For instance, this can be achieved by the inclusion of large cations in the case of zeolites or by controlling...
To estimate the performance and sustainability of enhanced geothermal systems (EGS), an accurate characterization of the fractures created by hydraulic stimulation is crucial. It is common practice to perform tracer tests to obtain relevant reservoir parameters such as reservoir impedance, potential production flow rate as well as fracture surface area [Shook, 2017]. The fracture surface area...
Colloidal particles released by various chemical and industrial processes penetrate soils and groundwater, and transport themselves other contaminants like heavy metals or PCBs. Thus, an accurate description of the transport and retention of these particles is required to prevent and manage environmental contamination, like the pollution of drinking water supplies. Literature stands that...
CO2 injection into reservoirs will change the state of stress in both reservoir and caprock formations due to poro-mechanical, thermal and chemical effects. As a result of induced stress, the caprock can be mechanically damaged or new fracture systems can be created. It is the objective of this study to determine the behavior of intact and fractured caprock when exposed to supercritical CO2 at...
The accurate determination of formation heating area is the basis for productivity evaluation and dynamic prediction of cyclic steam stimulation in heavy oil reservoirs. In early research, formation heating area is considered to be an isothermal region and its temperature has the value of injected steam temperature. In fact, as to our knowledge, the temperature of heating area gradually...
Injection of a generic naphthenic acid blend to injection brine has been shown to increase oil recovery. The purpose of this work is to analyze the effect of several individual naphthenic acids on the oil-water interfacial dynamics. Acids were selected based on water solubility and structure; analysis of different structural characteristics of various acid groups was made to determine a...
Grain partitioning of three-dimensional microtomography segmented images provides valuable in-situ properties and statistics that allow for accurate particle and structure characterization of porous media samples. There are many applications of this technology, ranging from analyzing core samples in petroleum engineering and soil science to developing novel structures in material science. This...
The aim of this study was to experimentally determine a relationship between gas residual saturation (SGR) and corresponding hydraulic conductivity (K) of two coarse sands. The SGR indicates the ratio of volume of entrapped air bubbles to pore volume of the sample.
Series of constant head infiltration-outflow experiments were used to determine the relationship between the K and the...
Arsenic is one among the most hazardous contaminants present in drinking water sources. Recent increases in agricultural growth and extensive use of fertilisers in India and Bangladesh have led to the release of naturally occurring arsenic from the rocks and earth's crust, creating a major public health issue in these countries. A novel technology has been recently developed that uses...
Adsorption-induced deformation has been found to manifest in numerous natural and engineering processes, e.g., drying of concrete, water-actuated movement of non-living plant tissues, swelling of coal and shale, etc. [1]. The driving force for the deformation is solvation pressure – the pressure that a fluid adsorbed in a nanopore exerts on the pore walls. Solvation pressure can be calculated...
Numerical instabilities at low capillary numbers is a problem that has been reported for different types of pore network models [2], and first to address the issue was Koplik and Lasseter [4]. As most practical applications are in this regime, such as water flow in fuel cell gas diffusion layers and flow of carbon dioxide some distance away from the injection well in carbon dioxide...
MIL-53 is a MOF porous structures which exhibits very pronounced flexibility. As a consequence, adsorption of CO2 causes its reversible structural transformation, induced by the host-guest interactions. Here, we present detailed molecular modeling study of adsorption of CO2 and CH4 in the intermediate structures of the MOF. We use 20 intermediate structures, between the open pore one and the...
Hydraulic fracturing is a major means to improve gas production which can form multi fractures and complex fracture network. Because of the permeability difference between the fracture network zone and the matrix zone, the composite fracture network system was proposed. We built a three zones coupled composite model to describe the fracture network. I zone indicates fracture network, which...
Pore-network modeling provides a platform to study the upscaling problems in two-phase flow in porous media by representing the pore structure with a network of links and linking the pore-scale physics to the larger network. However, the bottleneck in this approach is the necessity to solve the pore-pressure field at each time step which makes it more and more computationally expensive with...
Coupling of geochemical reactions with hydrological and mechanical processes in nano-porous carbonate rocks can lead to complex behaviors involving the change of pore topology (e.g., precipitation, dissolution, compaction) and mineralogy. Fluid-rock interactions also change hydrological, mechanical, and geophysical properties (e.g., permeability, rock strength, elastic, acoustic velocity)...
Filtration of contaminants out of air is vital for many industrial applications. In particular, we are interested in the technology of air filtration used in vacuum cleaners produced by Dyson Ltd. In this study, we focus on predicting and improving the efficiency of the filter media used in vacuum cleaners. Filter media are usually characterized by different criteria. The first one is energy...
Miscible displacements in porous media are investigated through nonlinear numerical simulations. At a relatively larger flow rate or a wider gap of Hele-Shaw cell, the inertia must be considered and its role needs to be carefully investigated. In the present study, the Reynolds number is used to quantify the inertial forces. Its effect is measured by examining the variations of viscous...
Surfactant flooding is a chemical enhanced oil recovery (cEOR) technique where a low concentration of surfactant is added to the injection water. The surfactant reduces the oil/brine interfacial tension which, in return, increases the capillary number favoring the viscous mobilization of (capillary) trapped oil. In order to reduce the residual oil saturation significantly, ultra-low...
Abstract: With the increasing demand of oil and gas resource in the world, the development of deep reservoir has become an inevitable trend. In order to investigate the coupled effects of rock elasto-plastic deformation, fluid flow and heat transfer in the process of hydraulic fracturing of deep reservoir, the mathematical model of hydraulic fracture propagation is established based on...
Hydraulic fracturing is an effective method to improve oil recovery by injecting massive fracturing fluid to create complex fracture networks. After that, the well is commonly shut down for a period to promote water uptake and appropriate shut-time is of vital importance. One effective way to predict shut-in time is to combine experimental results of spontaneous imbibition (SI) and...
In relation with the potential applications of CO2 foam technology on Enhanced Oil recovery and carbon geological storage, the paper experimentally and numerically investigated the foam assisted CO2 displacement process in a water/oil pre-saturated porous media. Computational Tomography (CT) technology is employed to visualize the transient sweep process of CO2 foam flow in porous media and...
Flotation tests in laboratories are commonly carried out using Denver flotation cells of laboratory size. Since economical and performance impacts due to equipment age can be less obvious at a laboratory-scale than at an industrial-scale, the condition of parts of the cell is overlooked. Maintenance of damaged or old parts might not be carried out. Usually, these parts are not properly...
Reactive transport in sandstones is of importance for applications including acid stimulation methods, contaminant remediation and carbon dioxide sequestration. Natural sandstones consist of various minerals. These different minerals can lead to large discrepancy in predicting petrophysical properties. Simulation results of multi-mineral and single mineral reactions are compared to illustrate...
Fiber-laden fracture fluid technology has been successfully implemented in unconventional reservoirs for fracture reorientation and fluid leak-off control. Inspired by the encouraging performance achieved in matrix stimulation, a new fiber-added treatment is employed for in-depth profile control, diverting injected fluids into less-permeable zones. The paper is aimed at: 1) highlighting the...
Creep/swelling of Shale-rocks create several problems [1] during underground drilling operations, such as stuck-pipe/drill-bit. However, creep/swelling of shale-rocks can close the gaps between rock (wellbore) and casing –therefore no cementing is needed – which can save a lot of time and money and such a “natural” closing ensures “no-leakage” during further drilling and production phases....
The assessment of the long-term safety of a deep underground repository for radioactive waste requires a comprehensive understanding of the system and appropriate numerical tools. RepoTREND is a final repository simulator being developed by GRS for simulating
- the release of contaminants and
- their transport through the near-field and far-field to the biosphere, including
- the...
Metal organic frameworks (MOFs) consist of metal oxide cores linked by multifunctional organic linkers, forming crystal-like structures with well-defined pore size. They are highly promising materials in a large variety of applications including gas storage, solvent separation, drug delivery, and catalysis. The guest-host interaction is of key importance for all these applications and...
Fractured vuggy carbonate reservoir is of diverse types, large scale and complex spatial structure. Traditional numerical simulation software is hard to describe, which brings great difficulties to production prediction. The project team to establish a simulation method of multiscale numerical hole, slot and hole unified oil gas water three-phase flow equations and medium flow solid coupling...
We quantify interactions between resident and infiltrating water coupled with tracer transport during water-air, drainage-imbibition cycles. Using a 2D Lattice Boltzmann method (LBM), we investigate immiscible-miscible and tracer transport processes in an heterogeneous pore structure with various boundary conditions. The simulations clearly show three types of interactions between resident and...
The PDEs governing multiphase flow and transport in heterogeneous porous media are highly nonlinear. Therefore, in the fully implicit finite-volume method, solving the algebraic systems is challenging and accounts for most of the simulation cost. We present a numerical scheme applicable to general-purpose simulation that reduces the computational cost by improving the nonlinear convergence....
Three-dimensionally ordered mesoporous (3DOm) carbon is produced by negative templating of spherical silica nanoparticles [1]. The final product represents a periodic nanostructure with spherical pores interconnected by openings. These materials are promising for application in separation and purification processes as adsorbents, and for natural gas storage of methane in the form of hydrates...
Soils and rocks are amongst all, the most challenging construction materials to be studied. Currently, the elastoplastic theory has become popular when it comes to modelling their stress-strain behavior. This is because this theory is capable of considering the material strengthening, softening, ultimate strength and residual strength. In this paper, we present an elastoplastic constitutive...
In contrast to the conventional reservoirs, shale reservoirs embody micro-pores developed from inorganic minerals and nano-pores developed from organic matters, which can both exert an important influence on two-phase flow properties. Through a bimodal pore-size distribution (PSD) in whole shale system verified by nitrogen absorption tests may be assumed as the Gaussian mixtures, the random...
The finite deformation of an unsaturated porous medium is the result of a complex interplay between capillary effects, interfacial area propagation, pressure diffusion and large deformations of the solid skeleton. Discrete approaches provide a means to integrate the physics of capillarity with deformation. However, discrete approaches only open the road to simple cases. The authors analysed...
Nano-Pore-throat are dominantly developed in shale，The flow of gas in the nano pore throat is different from that of the conventional pore throat. Shale flow has micro scale effects, and the flow is more complex, In order to establish the flow model and flow equation which can be used in the analysis of shale gas flow, In this paper, based on the single nanotube model , Combined with the...
Several emerging problems in geotechnical and geoenvironmental engineering pose multi-physics problems involving non-isothermal processes in unsaturated soils. Properly studying these problems requires the development of models for the Soil Water Retention Curve (SWRC) to describe the constitutive behavior of unsaturated soils under non-isothermal conditions. This study aims to develop...
The interest in viscoelastic surfactant solutions (VES) as enhanced oil recovery fluids has been increasing in recent years, due to their practical advantages over polymeric solutions. However, during their flow inside the porous medium, complex geometries (such as throats that connect pores) might cause high shear-extensional components, affecting the flow behavior, and therefore the...
The multi-stage fractured horizontal wells(MFHW) is the key technology for developing shale gas reservoirs. After the stimulated reservoir volume is fractured, the gas flowing in matrix is non-linear seepage controlled by the nano-scale pores, while the seepage in stimulated region is transformed into Darcy flow controlled by the micro-scale fracture network. In this paper, the steady-state...
X-ray Computed Tomography scanning is an innovative procedure that allows the internal structure of samples to be computed in 3D. It has completely revolutionized the way several measurements can be achieved in geoscience, including characterization of petrophysical properties of porous media. In order to provide accurate results, it is, of course, necessary to have high quality scan images,...
The current state-of-the-art modeling approaches for contaminant/heat transport in fractured rock include (1) discrete fracture-network (DFN) and discrete fracture-matrix (DFM) models with the fracture network and matrix blocks randomly generated, (2) numerical models based on conventional dual-continuum models, and (3) analytical models with simplified parallel fractures and slab-like matrix...
The Digital Rocks (https://www.digitalrocksportal.org) is the first platform of its kind for data management of images of rock microstructure. It allows preservation, curation, visualization and basic analysis of images of porous materials (and experiments on them). Imaging modalities include X-ray (micro)tomography, (focused ion beam) scattered electron microscopy, optical microscopy,...
Core analysis for characterization of rock properties such as permeability involves laboratory flow experiments often performed at lower temperature and pressure than the conditions typically present in subsurface hydrocarbon reservoirs. For gas permeability in particular, slippage flow can occur at reservoir conditions, resulting in higher apparent permeabilities than would occur for Darcy...
The surface element integration technique was used to systematically study Derjaguin-Landau-Verwey-Overbeek (DLVO) interaction energies/forces between hollow spherical particles (HPs) and a planar surface or two intercepting half planes under different ionic strength conditions. The inner and outer spheres of HPs were concentric (CHP) or in point contact (PHP). In comparison to a solid...
Immobilization of transition metal oxides on a solid support by impregnation with solutions of metal salts is a common route in catalyst design. An inherent difficulty of such methods is that precipitation by solvent evaporation leads to undesirably large catalyst crystallites forming at the outer surface of the porous support. In this study we explore the potential of an alternative route,...
Models for multiphase flow in porous media account for several complex physical phenomena such as PVT behavior and interplay with the porous rock, which altogether make reservoir simulation a challenging task. High aspect ratios and strong petrophysical heterogeneity impose severe timestep (CFL) restrictions, and implicit discretizations are thus usually preferred over explicit ones. In a...
Nanoparticles are emerging as an important advancement in the petroleum industry, including in enhanced oil recovery. Nanoparticles have shown potential to mitigate some of the issues associated with enhanced oil recovery due to their impact on bulk and interfacial properties. However, before their application in any EOR operation, the study of nanoparticle transport behavior in porous media...
The platform carbonate reservoirs in the Mishrif Formation of the HF Oilfield in Iraq are highly heterogeneous and can easily lead to water injection breakthrough along the high permeable thin layer to reduce the water injection sweep efficiency. Therefore, it is of great significance to clarify the main controlling factors of heterogeneity and formulate a reasonable development...
The impact of fuel spills on the unsaturated zone are one of the main environmental issues when licensing new fuel stations or industrial facilities where Underground Storage Tanks (UST) are used. The development and use of fate and transport models of organic pollutants (BTEX) on the vadose zone can therefore be used to understand the behavior of these pollutants under different...
Profile control is one main effective measure to increase oil production and reduce water cut during the later period of oilfield development. The gel particle is a widely used profile control agent, but the research of migration performance in the pore throat is little, which limits its application. Based on the Hertz contact theory, the theoretical model of gel particle transport through...
Digital rock analysis and pore scale studies have become an essential tool in the oil and gas industry to understand and predict the petrophysical and multiphase flow properties for the assessment and exploitation of hydrocarbon reserves [1]. The fundamental problem in pore-scale imaging and modelling is how to represent and model the different range of scales encountered in porous media, from...
Advances in imaging technologies and high-performance computing are making it possible to perform Direct Numerical Simulation (DNS) of flow processes at the pore scale; nevertheless, the restrictions on the physical size of the sample (porous rock) that can be fully resolved using Navier-Stokes-based DNS are quite severe. For samples on the order of a cm 3 , the complexity of the spatial...
In this study, polyvinylidene fluoride (PVDF) hollow fibers with different morphologies have been fabricated via a dry-jet wet spinning process and tested for membrane distillation (MD). The effects of PVDF content and solvents, dimethylacetamide (DMAc) and triethylphosphate (TEP), on the morphology, pore structure geometry and MD performance were investigated. Phase separation mechanism of...
Many tropic soils exhibit double- or even triple-porosity features as reflected by heterogeneous pore- and/or particle-size distributions. While the amount of clay in tropical soils is generally relatively high, cementation of the finer particles into larger grains make field soil often behave macroscopically more like coarse-textured media. Natural aggregation may further enhance preferential...
For the study of yield stress fluids flow in porous media, the complex pore-scale structure has been extensively idealized as bundles of capillaries. A bundle of rectilinear capillaries of circular cross-section has been used over the past decade for the development of a new method of pore-size distribution (PSD) characterization based on the injection of a yield stress fluid. The main idea of...
One of the longstanding challenges of the oil and gas industry is the problem of scale and hence, the term “upscaling” is used frequently in literature. In this work, we investigate the ways to represent connected regions with substantially different pore sizes. For this purpose, pore-scale simulations are combined with conventional continuum scale models. Our primary objective is to run...
Infiltration is the key hydrological process that affects a formation of runoff, floods generation, water erosion, and leaching of contaminants through soil. These processes are often most intensive in nearly saturated soils. An example of frequently highly saturated and intensively leached soils are the filter layers of the storm water infiltration swales, bioretention cells, and rain...
Development of unconventional shale gas reservoirs (SGRs) has been boosted by the advancements in two key technologies: horizontal drilling and multi-stage hydraulic fracturing. A large number of multi-stage fractured horizontal wells (MsFHW) have been drilled to enhance reservoir production performance. Gas flow in SGRs is a multi-mechanism process, including: desorption, diffusion, and...
Shale gas reservoirs generally develop micro fractures. During pressure-relief production, the change of micro-fracture width caused by stress-sensitivity is an important factor affecting shale gas transport. Based on the cubic grid model, the slippage flow model, the Knudsen diffusion model and the surface diffusion model, a gas mass transporting model considering the dynamic change of shale...
During the development of shale gas reservoir, large amount of hydraulic fracturing fluid are forcibly injected into the reservoir to create complex fracture networks. However, field data indicate that only a small fraction of the injected fluid can be recovered during the clean-up period. Except the mostly discussed reasons including capillary force, osmotic-force, and clay hydration, the...
Porous polymeric materials have a large variety of applications in many areas as highly selective membranes, selective adsorbents and filters, porous electrodes for fuel cells, sensors or insulators, etc. High crosslink density Cyanate Ester Resins (CERs) – also known as polycyanurates (PCNs) – are commonly used in aerospace applications and electronic devices as thermostable polymer...
Polymer flooding is one of the most commonly applied enhanced oil recovery technique. The main mechanism of polymer flooding is the increased sweep efficiency by increase injected water viscosity, which would reduce fingering, improve water injection profile and reduce the relative permeability of water flow. Meanwhile, viscoelasticity of polymer is suggested that it can improve displacement...
Viscous fingering--the fluid-mechanical instability that takes place when a low-viscosity fluid displaces a high-viscosity fluid--has traditionally been studied under either fully miscible or fully immiscible fluid systems. In practice, however, the miscibility between two fluids can change appreciably with temperature and pressure and often falls into the case of partial miscibility, where...
With the increasing application of nanomaterials for environmental remediation, modified nanoscale zero-valent iron (nZVI) particles have been extensively examined in terms of their enhanced mobility in porous media as compared to bare nZVI particles. However, the monitoring of nZVI particle transport processes in low permeability media is still a challenge. To quantify the particle transport...
The DECOVALEX project is an international research and model comparison collaboration for advancing the understanding and modeling of coupled thermo-hydro-mechanical (THM) processes in geological systems. Prediction of these coupled effects is an essential part of the safety assessment of geologic disposal systems for radioactive waste and spent nuclear fuel, but also for a range of other...
In this study, we analyze the filter cake formed due to mono and bi-dispersed spherical particles. The particle-particle, particle-filter interactions are simulated using Discrete Element Method (DEM) and the fluid flow is simulated using Finite Volume Method (FVM). The computation of the two-way particle-fluid interaction is the challenging part in the numerical studies mainly due to the...
As a mesoscopic kinetic approach, the lattice Boltzmann method (LBM) has been widely applied to characterize the flows in porous medium. However, for larger scale flow, upscaling microscale technique is the key and difficult point. Based on microtomographic images of an actual coal sample, numerical simulations were carried out using the LBM at the pore scale. The velocity/pressure...
Colloidal particles released by various chemical and industrial processes penetrate soils and groundwater, and transport themselves other contaminants like heavy metals or PCBs. Thus, an accurate description of the transport and retention of these particles is required to prevent and manage environmental contamination, like the pollution of drinking water supplies. Literature stands that...
We investigate the properties of the electrically conductive polymer Polypyrrole (PPy) in tubular pores of monolithic micro (pore diameter D < 2 nm)-, meso- (2 nm < D <20 nm) and macroporous (D > 50 nm) silicon. We successfully demonstrate a homogeneous filling via electro-polymerisation for the extremely anisotropic confinement of 12 nm pore diameter and 180 µm pore length. The kinetics of...
Mass transfer in field-scale discrete fracture networks (DFNs) is affected by the erratic internal structure and hydrogeological properties of the fractured media, which can result in non-Darcian flow due to channeling flow and non-Fickian transport due to matrix diffusion competing with fast displacement along fractures. This study explores flow and transport dynamics in various DFNs with a...
The orientational and translational order of a thermotropic ferroelectric liquid crystal (2MBOCBC) imbibed in self-organized, parallel, cylindrical pores with radii of 10, 15, or 20 nm in anodic aluminium oxide monoliths (AAO) are explored by high-resolution linear and circular optical birefringence as well as neutron diffraction texture analysis. The results are compared to experiments on the...
Permeability anisotropy is a common feature of hydrocarbon reservoirs. In practice, hydraulic fracturing has been an effective technique for enhancing the productivity of wells in low permeability reservoirs. However, most study about hydraulic fractures focuses on isotropic reservoirs and few literatures discussed the effect of permeability anisotropy and azimuth angle of fractures on the...
A new direct inverse method is developed that is capable of simultaneous estimation of hydraulic conductivity (K), boundary conditions, and flow field for both confined and unconfined aquifers. In this research, the direct inverse method is applied to the inversion of discrete fractured aquifers. By sampling synthetic aquifer problems with different fracture patterns, the inverse method is...
The design of a field-scale injection of engineered nanoparticle (NP) suspensions for the remediation of a polluted site requires the development of quantitative predictive models for the system design and implementation.
In general, micro- and nanoparticle transport in porous media is controlled by particle-particle and particle-porous media interactions, which are in turn affected by flow...
Pore network modeling is a technique that has been booming in recent years, and several authors have used it to obtain properties as absolute permeability, relative permeabilities and capillary pressures, which are common obtained from laboratory tests and/or experimental correlations. The scope of this work is to model flow and immiscible displacement and estimate fluid flow properties such...
Development in the dry unconventional gas-bearing Marcellus Shale in the Eastern United States has grown rapidly over the past decade. When a well is fractured in the Marcellus, only a small proportion of the slickwater fracturing fluid, typically <10%, is produced back following well completion. Most analyses also suggest that existing fracking and production practices only produce a...
The direct numerical simulations (DNS) experience of pore-scale flow is still relatively scarce and laborious due to the numerous practical challenges. They include typically huge model size and high computational expenses, some uncertainties in geometrical description related to resolution size and other factors remaining much in common for single and multiphase flow cases. Sometimes this...
Characterization of geologic heterogeneity is crucial for reliable and cost-effective subsurface management operations, especially in problems that involve complex physics such as deep aquifer storage of carbon dioxide. With recent advances in computational power and sensor technology, large-scale aquifer characterization using various types of measurements has been a promising approach to...
The densities of Minkowski functionals (volume, surface, mean curvature and total curvature) represent a complete set of independent global microstructural descriptors [1-3], as a consequence of Hadwiger’s characterization theorem [4]. Similar to correlation functions [5, 6] they offer a systematic and principally automatizable approach for the quantitative description of microstructures, but...
A standard approach to model diffusion in porous media is the assumption of the validity of Fick‘s Law. Although widely used, that description can only be employed for binary mixtures or low concentrations of the components as it neglects molecular interactions of the different species.
When looking e.g. at gas migration of an organic component in soil where higher concentrations of...
In-situ leaching of ores is considered as an economic and environmentally friendly production method. However, the leaching process is complicated by its dependence on the material’s heterogeneity and by retroactive effects over large scales. We developed an experimental procedure which is based on positron emission tomography (PET) during transport experiments with radiotracers (Kulenkampff...
The world is running out of fossil fuels and the products of their burning in air (mostly CO2) have already impacted global climate. Today it is clear that in near future we need to convert the global energy economy towards cleaner and renewable fuels (like hydrogen). However, to efficiently store hydrogen at ambient temperature and not too high pressures, we need to develop the hydrogen...
A new simulation model for solvent-aided thermal recovery of heavy oil and bitumen has been developed. The simulation model describes non-isothermal, multiphase, and multicomponent reservoir systems involving multiple kinetic reactions of heavy oil cracking. In the development of numerical simulator, we include 12 fluid-and-solid components in four phases of 1) aqueous, 2) liquid organic, 3)...
The numerical simulation of subsurface processes requires efficient and robust methods due to the large scales and the complex geometries involved. To resolve such complex geometries, corner-point grids are the industry standard to spatially discretize geological formations. Such grids include non-planar, non-matching and degenerated faces. The standard scheme used in industrial codes is the...
Permeability prediction of porous media is be of great significance for both petroleum and environment fields. The permeability of a porous medium can be directly calculated based on one 2D thin section. However, it is often doubtful. Therefore, a new technique of the permeability prediction from a 2D thin section is proposed. First 3D porous media is reconstructed from a 2D image using...
We present a simple single-pressure dynamic network simulator for two-phase flow in porous media with a focus on exploring the limits of a single-pressure network model.
Our work builds upon the work of Aker et al.[1] and Knudsen et al.[2], where we aim to more accurately describe and model the interactions of ganglia moving through the porous material. Whereas the previous models assumed...
The pore and throat size of the global unconventional oil and gas reservoir is mainly nano-scale, and the minimum radius is evenly about 1 nm. The characteristics of the unconventional oil reservoir depend greatly on the micro pore structure of the reservoir. Its main contents include the shape, size, quantity, connectivity and distribution characteristics of reservoir pores and throats. The...
In laboratory steady-state measurements of relative permeability, capillary discontinuities at sample ends give rise to capillary end-effects (CEE) and keep a higher water saturation toward the core end. The water saturation measured is higher than ideal saturation without CEE and result of erroneous relative permeability curves[1] finally. Especially in tight sand cores, high capillary force...
For further research on the effect of heavy oil viscosity on the fracture geometry, this paper establishes heavy oil fracturing model and conventional fracturing model based on thermal-hydraulic-mechanical (THM) coupled theory, Walther viscosity model and K-D-R temperature model. We take viscosity and density within heavy oil fracturing model as functions of pressure and temperature, while...
Pore network models have been applied for predicting petrophysical properties at pore scale. From a geometry point of view, basically a pore network and pore and throat size distributions are required for pore network modeling. Although different pore network models have been constructed using data extracted mainly from images, it is not always possible to count on the necessary information,...
The structure of nanopore in shale is complex, multiple gas migration mechanisms coexist. In this paper, we have used a bundle of tortuous capillary tubes with different diameters to represent porous structure of shale considering slippage effect and Knudsen diffusion and surface diffusion. Fractal theory is applied to mathematically express the capillary diameter distribution and their...
Characteristic of Coal Pore Structure and Its Relationship with Sedimentary Environment in Hegang Basin
Wang You-zhi1 , MaoCui2
（1.Exploration and Development Research Institute of Daqing Oilfield Company Ltd.，Heilongjiang, Daqing 163712, China
2.School of Geosciences, Northeast Petroleum University, Heilongjiang, Daqing 163318, China）
Abstract:Base on low temperature nitrogen adsorption...
Using the fresh oil⁃bearing core samples, this paper studied the remaining oil micro⁃distribution or occurrence and the influence of long⁃term waterflooding on the reservoir pore structures in major reservoir of Laojunmiao oilfleld in Yumen. The study indicates that the remaining oil occurrence in the reservoir is dominated by film or interstitial form, and the pore stucture is the key factor...
Accurate and efficient numerical simulation of fractured reservoirs is important and challenging. Conventional dual porosity and dual permeability(DP/DK) models are efficient but not accurate, especially when fracture-diagnostic tools make it easier to get the detail of the complex fracture networks. Discrete-fracture models(DFM) have been developed to use information of fracture networks,...
Multi-phase flow process in porous medium are generally simulated with in introduction of relative permeability, which is assumed to be a scalar function of phase saturation. Previous research have demonstrated this assumption might not be suitable for capillary force dominated heterogeneous porous medium. Similarly, in vugular porous medium, the free flow region in vugs would introduce...
Keywords:
Droplet flow regimes, Interfacial dynamics, Volume of Fluid method, Parasitic currents, Direct Numerical Simulations
Abstract:
Multiphase flow in microfluidic devices that produce identical droplets/ bubbles at a known frequency has gained attention due to its use in biomedical, chemical and engineering applications.
In this numerical study, we investigate the flow dynamics...
Heterogeneous carbonate rocks, especially coquinas, present several challenges regarding their morphological characterization, petrophysical parameterization, and obtained a more complete understanding of their fluid flow properties. Within this context, a workflow is proposed and analyzed for digital petrophysics using a combination of experimental data and numerical 3D fluid flow...
Hydraulic fracturing is one of the most effective treatment methods in development of low permeability reservoir which improve the conductivity of the formation such that the reservoir liquids seepage capacity is enhanced with flow friction reduced, which highly increase the withdrawal of underground liquid. However, with the existing of hydraulic fractures and due to the complication of their...
Carbon dioxide (CO2) diffusion in dual-porosity plays a great important role for effective flow in tight oil reservoir. The CO2 diffusion coefficient in matrix is different with the coefficient in fracture because of micro-scale effect. Matrix diffusion coefficient and fracture diffusion coefficient was introduced and respectively used into matrix flow model and fracture flow model. Using...
Aiming the heterogeneity of low permeability carbonate reservoir in M group of H oilfield, carried out the physical simulation experiment of multi-layer waterflooding, and based on the T2 relaxation spectrum technique, studied the micro distribution of residual oil and production degree of different permeability combination. Results show that to the different pore structure types, NMR tests...
Considering the sensitivity of microorganisms to the different environment, the microbial growth kinetics equation was improved, and a 3D two-phase five-component mathematical model which could fully reflect the microbial flooding process in the reservoir medium was established. The components of the model involve oil, water, microbe, nutrient and metabolite. The model integrates the effects...
In this paper, we studied the numerical simulation of shale gas reservoir with both hydraulic fractures and natural fractures using the embedded discrete fracture system. First, the 3D DFN (discrete fracture network) model was built according to the real geological state. Then, transmissibilities between the embedded fracture grid and the matrix grid are calculated using two different methods....
Abstract: The numerical simulation of pore scale seepage in porous media is of great significance for the development of new energy sources, such as shale gas and geothermal energy. In the past few years, many scholars have developed the numerical method including finite volume method (FVM), Lattice Boltzmann Method (LBM) and molecular dynamics to achieve this simulation in different levels....
Tight porous media have the characteristics of extremely low permeability and the permeability of it is sensitive to the effective stress. Stimulated reservoir volume (SRV) is usually performed to improve the production of well in tight porous media. The SRV zone is usually considered as a dual-porosity medium in well test or numerical simulation due to the computationally efficient. The shape...
Polymer flooding is an effective way to enhance the recovery rate of heavy oil reservoirs in high water-cut stage. To overcome the commonly existing defects of general polymer injection such as high costs and high transmissibility pathways. Multi-stage concentration polymer flooding and optimization methods are researched to clear out its influence on heterogeneous reservoir recovery...
Pore scale flow simulations in reservoir rocks heavily depend on characterizing and modeling of the pore space. Single scale and multiscale pore network extraction from micro-CT images are going through extensive development. However, the choice of pore network extractions method is sensitive to the rock nature (homogenous, complex or microporous). Additionally, the success of the pore network...
Different injected media huff and puff is a promising enhanced oil recovery approach in tight oil reservoirs, which can effectively supply formation energy and enhance the productivity of individual well. And there still exists many uncertainties of oil recovery mechanism in the process. In this study the experiment method of cyclic water injection and carbon dioxide huff and puff in tight...
Hydraulic fracture has become an essential well stimulation technique in tight oil reservoirs. Large-scale vertical well fracturing can generate longer vertically oriented fractures to increase drainage area and, therefore enhance production and recovery efficiency of single well while also save costs[1]. The aim of this study is to develop a more practical productivity forecast model that can...
In order to achieve gas kick early detection outside the riser, the ultrasonic propagation law in gas-liquid two-phase flow of riser annulus need to be analyzed. Therefore this paper aims to explore the ultrasonic propagation law in gas-liquid two-phase flow of riser annulus under different conditions and to establish a quantitative relationship between the ultrasonic signals and gas void...
We present a two-phase multicomponent reactive pore-scale model based on Direct Numerical Simulation of the Navier-Stokes equations using the Volume-Of-Fluid and the Continuous Species Transfer methods. In order to study wettability change during low-salinity flooding, simple upscaling rules from the nano-scale to the pore-scale are integrated to the model to describe (1) change of local...
We have performed ultrasonic measurements on porous glass filled with liquid capillary condensate. Reducing the vapor pressures induces the formation of concave menisci at the pore ends and enables us to vary the adsorption-induced pore pressure in a controlled way [1,2]. Measuring simultaneously the propagation of longitudinal and transversal waves we evaluate the temperature and the...
Microaggregates are the fundamental building blocks of soils and thus important for its structure, properties and functions [Totsche et al]. Although there has been much research on the links, dynamics, stability, and structure of soil microaggregates, there is still a substantial lack of quantifying the relationships between the key factors of their dynamics. Those key factors are soil fauna,...
Porous media can be viewed as a special type of two-phase composites (with one phase being the void phase or possibly vacuum) or as metamaterials (i.e. materials with microstructures that are principally similar to macroscopic architectural structures, from which they differ only by scale) [1,2]. In this contribution we investigate the effective elastic constants of isotropic and cubic porous...
Carbonate reservoirs hold almost half of the world’s oil and gas reserves. Many giants carbonate fields are rather mature, been producing for 50 or even 100 years; these are ready for some form of gas-flooding, EOR. More precise reservoir characterization can lead to better modeling of EOR schemes for these giant/mature fields.
Characterization of carbonate reservoirs is a complicated task...
Most approaches to stimulation of horizontal wellbores rely on initiation and growth of more than one hydraulic fracture. In the ideal case, each perforation cluster generates at least one hydraulic fracture, and the fluid and proppant are uniformly partitioned among these entry points. Simulation of this richly-coupled process of multiple fracture growth is an active area of research. But how...
Current hydrocarbon recovery methods in hydraulically fractured shale have low recovery efficiency of about 10%. The objective of this work is to investigate several enhanced recovery methods to improve the production rates in shale. We examine the effectiveness of nitrogen and supercritical carbon dioxide in huff-and-puff methods for enhanced oil recovery to re-energize the reservoirs and...
For a non-isothermal reactive flow process, effective properties such as permeability and heat conductivity change as the underlying pore structure evolves. We investigate changes of the effective properties for a two-dimensional periodic porous medium as the grain geometry changes. We consider specific grain shapes and study the evolution by solving the cell problems numerically for an...
The fluid injection involved in CO2 sequestration will result in a change in formation pressure and stress state, which may induce fracture initiation and pose a danger to the long-term secure carbon storage. This work attempts to study fracture initiation based on grain-scale fluid-rock interactions.
CFD-DEM model involves the discrete element modeling (DEM) of solid granular medium and...
Photonic colloidal crystals, also referred to as artificial opals, are well-known systems that, relying on their photonic properties, have wide applicability in many fields such as photonics, sensing, light harvesting, etc. Recently, latest knowledge on their ability to adsorb and confine fluids, and correspondingly transduce to photonic response [1-3] allowed to envisage new perspectives...
Pore-scale surface roughness occurs in varying degrees and forms within geologic media due to authigenic cement coatings and clay minerals. Such roughness increases the surface area contacted by fluids and chemical additives during subsurface operations such as enhanced oil recovery, storage of hazardous waste, carbon storage and sequestration, and non-aqueous phase liquid (NAPL) remediation...
This talk will focus on the numerical aspects of reactive flows and pore-scale modeling, and how involving vortex-like methods can substantially improve computational efficiency, that is to say optimize the use of computing resources (computational time and memory storage). After briefly describing the numerical approach, a few numerical simulations of calcite dissolution will be...
PEM fuel cells are promising zero emission power sources. They are alternatives for fossil fuels in automotive industry. In a PEM fuel cell transport of the reactants is the function of bipolar plates. Afterwards, gas diffusion layer (GDL) distribute the reactants on the membrane. Thus, the gas transport to the membrane electrode assembly (MEA) is governed by convection in bipolar plates and...
Reactive flows and transport models through the porous medium are important for a wide range of scientific and industrial processes. Examples in this sense are groundwater remediation, oil recovery from reservoirs, CO2 sequestration etc. The main goal of the research is to develop mathematical models that describe such processes at the pore scale and to derive effective models at the macro...
A two- or three-dimensional nonlinear model for the inertial incompressible viscous fluid flow at a
fluid-porous interface is proposed [1]. The interfacial region between the pure fluid and the homogeneous porous region is viewed as a thin transition porous layer characterized by evolving heterogeneities [2-4]. An asymptotic analysis [5] is applied to the homogenized Navier-Stokes equation...
Crack propagation in silica may be enhanced in aqueous solution due to protonation of the silica surface and chemical reactions between the solution and strained siloxane bonds at the crack tip. To identify the coupled chemo-mechanical processes which govern silica fracture in the presence of pure and salt water, sub-critical fracture in amorphous silica has been investigated using molecular...
The study of fluid-flow through porous materials is of high relevance in a wide variety of applications such as geothermal energy exploration and generation, CO2 sequestration and oil and gas reservoirs management. Physical experiments are not always convenient or even feasible, due to the nature of the materials. A suitable alternative is to realize Direct Numerical Simulations with micro-CT...
We present a reactive fluid dynamics modelling approach coupling flow physics and geochemical calculations at pore scale resolution. A model workflow combining numerical solvers has been developed according to the operator splitting approach and the Lagrangian transport method. The FlowDict module of the GeoDict software package (Math2Market GmbH, Germany) iteratively computes the flow field...
Ultrafiltration membranes have a wide range of applications from drug delivery to water purification and virus filtration (Dorin et al. 2014; Li et al. 2017). A class of ultrafiltration membranes that has received much attention is the past decade is block copolymer membranes synthesized by self-assembly and non-solvent induced phase separation (SNIPS). These polymer membranes often exhibit an...
Motivated by geothermal energy storage in the subsurface, we undertake a formal derivation of a linear poro-thermo-elastic system within the quasi-static framework. This derivation is based upon the well known derivation of the quasi-static poroelastic equations (also known as the Biot consolidation model) from the micro structure, except that we now include energy conservation equations in...
Micromodels are a proven platform for offering new insights into the area of foam enhanced oil recovery (EOR). These tools provide us with not only analytical information for the characterization of particular oil-surfactant systems but also allow us to gain fundamental insight into the mechanisms that drive the oil displacement process. In addition, the polymer-based micromodels we use offer...
Foods provide challenging settings for testing porous media physics-based theories. Foods are heterogeneous materials composed of macromolecules such as carbohydrates, proteins, and lipids with continuously evolving structures and material properties during processing. Treating foods as porous materials to model the fundamental transport mechanisms and their effect on product quality is of...
The preheating start-up is an indispensable and vital phase before converting to SAGD process. It is mainly achieved through steam circulation or stimulation. Either way, the preheating time and steam consumption is usually over 5 months and 30,000 tons, respectively, especially for well pairs in reservoir with bottom transition zone or widely distributed mudstone. Thus, a pilot test about...
Recent progress in extraction of unconventional hydrocarbon resources, in particular shale gas, has ignited the interest in the studies of fluid-saturated nanoporous media. Since many thermodynamic and mechanical properties of nanoscale solids and fluids differ from the analogous bulk materials, it is not obvious whether wave propagation in nanoporous media can be described using the same...
Permeability of Luhui granite with 200mm in diameter and 400mm long was measured at triaxial stresses and elevated temperature using 600℃20MN servo-controlled triaxial rock mechanics testing machine. It is found that 300℃ is the threshold temperature (Tc) of permeability change with temperature in thermally cracked granite. The magnitude of permeability is 10-7D with a low increase below Tc...
Two-phase flow problems and reactive flow with changing pore geometry both include a free boundary at the pore scale. Chemical reactions as mineral precipitation and dissolution can alter the pore structure; hence the fluid-grain interface evolves following the reaction rates. The presence of two immiscible fluids introduces an evolving fluid-fluid interface depending on the flow itself and...
Capillarity driven lab-on-chips (LOC) are small cheap devices dedicated to perform diagnostics autonomously. To operate the chips, fluids flow in functionalized porous channels. Performance of the LOC however depends on the microporous fluid flow characteristics of the device. Pore-network (PN) models are a powerful tool to investigate transport phenomena at the pore scale while avoiding...
Food-grade surfactants Lecithin (from soy) and Tween 80 (used in food such as ice-cream) were employed for the mobilization of non-aqueous-phase liquids from porous media. The hypothesis of this work was that food grade surfactants can be employed for oil-spill remediation and that there may be a synergistic benefit when two surfactants are combined. The non-aqueous phase of this project was...
Objectives/Scope:
The understanding of proppant transport plays a critical role in estimating propped fracture dimensions and performance. Existing models generally assume a vertical planar geometry, whereas the reality in the subsurface may be much more complex. We use the discrete element method to simulate field scale proppant transport in complex fracture networks. Our results show that...
Tomographic 3D imaging at the pore scale provides an accurate geometrical representation of the microstructure of porous networks in oil reservoir rocks. Flow simulation models deployed on top of such geometrical representation unveil a variety of phenomena and allow estimating oil recovery parameters as part of reservoir assessment, management and operation. Physical models based on...
Propagation of proton fronts exerts a fundamental control on geochemical processes and contaminant transport in subsurface systems (Muniruzzaman & Rolle, 2015). Protons are of key importance in pore water solutions since they affect the sorption behavior of charged contaminants by setting the surface charge at the mineral-liquid interface. Therefore, it is of primary importance to enhance our...
Calibration of reservoir model characteristics by integration of well test data remains an important research topic. Traditional approaches to well test interpretation have relied upon simple homogeneous reservoir models, while the industry’s ability to develop more detailed and more heterogeneous static reservoir models has increased significantly. Pressure and rate data recorded at...
Wood fiber based materials are of high interest in building insulation. Their application is desirable due to the sustainability of renewable resources. Furthermore, wood fiber based materials outmatch petrochemical based materials with respect to health aspects during process and application.
The insulation properties of such fiber based materials are often characterized experimentally,...
Understanding the evolution of porous media is essential for many subsurface energy applications, including subsurface storage, shale gas production, fracking, CO2 sequestration, nuclear waste storage, and geothermal energy extraction. Both mineral composition and the intial pore structure of the medium play a significant role in this evolution. Conventional Darcy-scale models treat porous...
Surface-driven flows (also called osmotic flows) are generated at interfaces by various thermodynamic gradients (e.g. electric potential gradient: electro-osmosis, solute concentration gradient: diffusio-osmosis, temperature gradient: thermos-osmosis). They represent powerful tools to manipulate liquids in micro and nanofluidic systems, and play a key role in living systems, in sustainable...
The hysteretic relationship between capillary pressure (Pc) on saturation (S) has been shown to be a projection of a higher-dimensional surface that depends on interfacial area per volume (IAV) as the additional state variable. Most studies that validate the capillary-pressure–saturation-IAV relationship are performed on 2D micro-models or cores where scanning is performed in pressure and not...
Hierarchical porous materials such as hierarchical zeolites, which combine several porosity scales, are widely used in industry (adsorption, separation, catalysis) to overcome slow diffusion in microporous solids (< 2 nm) and enhance access to their large surface area. Available modeling approaches for adsorption and transport in such multiscale porous media are limited to empirical parameters...
Understanding reactions in porous materials impacts a wide range of applications including CO2 sequestration, hydraulic fracturing, design of energy storage systems, and supported catalysts. Particularly, the fundamental problem of crystal formation in porous materials raises two important questions: how is the crystallization process affected by the confined space [1], and how can we control...
The presence of contaminants in low permeability zones of aquifer can represent a real limitation for a complete and effective groundwater restoration. When dissolved plume encounter low permeability layers, concentration gradient between low and high-permeability zones determines storage of dissolved pollutants into the lower permeability layers by molecular diffusion (Forward-Diffusion)....
Transport processes in low permeability materials are likely to be dominated by fracture flow as found in fluid production in shale oil and gas reservoirs and in crystalline-rock geothermal systems. Fracture behavior in these systems is typically studied using saw-cut, laboratory fractured or “natural” fractured specimens that provide useful data on idealized fractures but that do not provide...
Fibrous structures are present in many materials, including non-woven filter media used for filtration, carbon-fiber reinforced plastics or glass-fiber reinforced plastics used in mechanical applications, or gas-diffusion layers used in fuel cells. Spatial distribution, orientation, length, curvature and center line of fibers in materials like these are essential characteristics needed to know...
Ceramic foams play a crucial role in thermal engineering, as their porosity confers interesting properties which, combined with their high-temperature stability, allows them to meet both heat exchange and heat insulation demands. To facilitate optimization of the pore-scale morphology, numerous techniques have been developed to generate periodic representative volume elements (RVEs) of the...
We derive the entropy production for transport of heat and two immiscible fluids in an inelastic porous material. The representative volume element (REV) is described by its mass, energy and entropy, and a Gibbs equation from which we define the temperature, pressure and chemical potentials (T,p, μi) of the REV.
The constitutive equations that follow from the entropy production of the REV...
In their seminal work, Saffman and Taylor showed that the displacement of a more viscous fluid by a less viscous one in a Hele-Shaw cell, as an analogue porous medium, leads to an interfacial instability. This description, however, neglects the inherent disorder in porous media, as well as the non-hydrodynamic interactions between the fluids with the solid surfaces. Here, we revisit the...
The mechanical and hydraulic response of granular media in partially saturated conditions can be highly intricate and requires proper understanding at the pore scale. The response of partially saturated sands to complex loadings such as projectile penetration necessitates integrating capillary suction in the constitutive model framework. In this study, Soil Water Suction Curve (SWCC)...
Colloidal facilitated transport of contaminants is a major concern for transport of low solubility chemicals in ground water flows. Compared with themselves alone, contaminants travel much further after adsorbing to natural colloidal particles, as far as kilometers over years. Therefore, understanding the transport behavior of colloids would provide insightful knowledge for environmental...
Microbial Enhanced Oil Recovery (MEOR) is a tertiary oil recovery technique that uses the bacteria and the resulting bio-products to increase oil production. Interfacial tension reduction and selective clogging caused by bacterial growth are the two mechanisms that have the dominating influence in MEOR. Due to lack of information about the chemical properties of bacteria and the...
Transport of water vapor through a membrane with nano- or micropores while being impermeable to liquid water is the basis for many fabrics and materials with widespread use. An application of the concept is membrane distillation (Lawson and Lloyd, 1997), where a temperature difference across the membrane drives transport of heat and mass. The transport is component selective and can purify the...
In-situ combustion (ISC) is an important thermal enhanced oil recovery technique. Significant open ISC questions are raised including the effect of coke formation on the pore structure and permeability during high temperature reaction in ISC process. In this study, a combination of X-ray computed microtomography (uCT) and LB simulation was used to evaluate the alteration of the geometric...
Current thermal methods for bitumen recovery are effective but require both environmental and economic performance improvements. Solvent based recovery method is an alternative to steam injection that has the potential to reduce greenhouse gas emissions associated with recovery. However, the pore-scale behavior of the solvent-bitumen system is very complex and poorly characterized to date. In...
Porous materials find frequent use in numerous thermal applications, offering a strong reduction of the total heat flow. Typical applications can be found in the automotive industry and aerospace engineering for the protection of sensitive components, but also in the building industry where heat losses through the opaque building components still account for a large part of the needed heating...
The traditional fixed-bed reactor design is ususally based on empirical correlations of plug flow pattern. This empirical method is usually not suitable for the low tube-to-particle diameter ratios (N=D/d< 4) where the local phenomena of channeling near the wall and the backflow in the bed are dominant. The recent “solid particle” method1 is too complicated for mesh generation, especially for...
International Space Exploration Coordination Group plans a long-term human space mission on the Moon or near Earth’s asteroids to make a pass to Mars. Food supply as well as recycling atmosphere and water is one of the largest concerns on the long-term human space mission. Growing plants during the mission in a spacecraft or a base may ease those concerns. Water movement in a substrate is an...
In an effort in evaluating the effectiveness of enhanced oil recovery (EOR) techniques and geologic carbon storage (GCS), significant interest is recently growing in using microfluidic experiments. On the other hand, because solving the Navier-Stokes equation at complex pore geometry of natural porous media requires extensive computational resource and time, simulation techniques in simplified...
This article describes the direct comparison between pore-level computations on a spherical-void-phase (SVP) porous material and volume-averaged computations done for the same domain. Pore- level simulations are conducted on random SVP geometries generated using the Discrete Element Modelling (DEM) approach developed by Dyck & Straatman [1] over a range of flow and heating conditions. ...
It has been known for a long time that there are cases where Darcy’s law does not
apply, also for single phase flow with small capillary numbers [1–4]. The flow rate has for
some cases been found to be proportional to the pressure gradient raised to the power
1/n where n 6 = 1. For other cases it has been found to be a threshold pressure, below
which no flow occurs.
Non-equilibrium molecular...
Transport through cement-based materials depends strongly on their3D microstructure. To evaluate transport and related processes at time and spatial scales beyond experimental data, and to gain in depth understanding of the critical role of the microstructure, numerical simulations are necessary. This, however, requires an accurate description of the 3D microstructures involved. However, for...
Mineral dissolution and precipitation reactions in porous media can alter formation properties, including porosity and permeability, in complex ways. While porosity increases with mineral dissolution and decreases with mineral precipitation, permeability alterations largely depend on the location of reactions in individual pores and the greater pore network. Pore network models enable...
Multiphase flow through fractured porous media has been of a great interest for decades because fractures can be the dominant flow paths in a wide range of environments, from groundwater flow and geothermal transport to fractured oil reservoirs and caprock integrity for gas and carbon storage projects. The fundamentals of multiphase flow in fractures have been studied both experimentally,...
Natural and injected fluids in the subsurface often vary in composition and have different physical properties such as density and viscosity. It is well known that fracture aperture distributions control flow, transport, and mixing of fluids within a fracture. In this study, the effect of fracture orientation on fluid mixing is examined for two cases with a density contrast (1) between...
Crop production using soil on Moon or Mars will be needed for a long-duration space mission. Water movement in porous media under microgravity must be known for agriculture in space. Water in porous media is mainly moved by a matric potential gradient. According to previous research, water movement in soil is extremely slower under microgravity than under 1G although a capillary force, which...
Swelling of clay minerals play an important role in many fields including gas and oil industry and 〖CO〗_2 sequestration. More than 60 percent of sedimentary samples in the US are of different types of mixed layer clays. We used molecular dynamics simulations to investigate the effects of layer charge location, interlayer cations (K^+ and 〖Na〗^+) and their concentration ratio on swelling of...
A reservoir-scale numerical model was developed with the use of multi-phase reactive transport code TOUGHREACT to estimate porosity, permeability and mineral composition changes of Lower Tuscaloosa (LT) sandstone formation and Marine Shale (MS) caprock overlying LT formation when CO2 is injected into LT formation. The reservoir-scale numerical model was developed based on geological settings...
Geometrical straining of particles in porous media is of critical importance in a broad range of natural and industrial settings, such as the contaminants transport in aquifers and the permeability decline due to pore plugging in oil reservoirs. Despite its importance, relatively few studies have been performed on particle straining under fluid-driven flows in porous media. Pore-network...
The effective thermal conductivity of porous materials is determined by all details of their microstructure. Since lower bounds (both Wiener and Hashin-Shtrikman bounds) are not available for porous materials (with vacuous voids), all predictions based on the porosity alone are necessarily model-based and thus tentative. In this contribution we first recall the exact solution of the...
Despite recent advances in synthesis and manufacturing of porous materials and devices, producing porous structures with targeted properties is still an expensive, trial-and-error procedure. Numerical porous media design is one of the possible ways to accelerate this process and to guide manufacturing.
Current numerical porous media design methodologies often include a random microstructure...
Fractures are crucial in the physics of geological media and have specific characteristics different from the surrounding rock matrix. Addressing their bulk hydraulic behavior is challenged by the multiscale fracture heterogeneities without any obvious homogenization scale and persistent high-flow channeling. Predictive flow simulations based on geological characterization are essential but...
We use microimaging to study the effects of flow rate on three-dimensional growth of biofilm in porous media. Three flow rates were investigated in model packed-bed columns, while biofilm was grown over a period of 11 days. At the end of the growth period, all columns were scanned using x-ray computed microtomography and a barium sulfate-based contrast agent to distinguish the biofilm. We used...
The design of accurate multiscale domain decomposition methods for channelized, high-contrast porous media remains as an important challenge in typical problems posed by the oil industry.
Here we investigate an improved version of the recently proposed Multiscale Robin Coupled method (MRCM) [1]. This method ensures weak continuity of both normal fluxes and pressure through the imposition of...
The talk is concerned with a novel discrete fracture model for single-phase flow in aquifers with highly permeable fractures, which are assumed to be filled with a porous medium different from the porous medium in the surrounding matrix rock. The fractures are treated as a ($n-1$)-dimensional interface in a $n$-dimensional domain. The finite element method couples the flow in the fracture and...
Terzaghi’s Principle states that the total stress acting on a porous material can be decomposed linearly into a part that acts on the solid porous structure and the fluid pressure. The result of the Terzaghi’s Principle is that the stress-strain relationship for porous media does not have to be re-constructed for every possible fluid pressure – increasing the fluid pressure linearly effects...
Introduction
The Development of an environmentally sustainable method for the extraction and processing of Rare Earth Elements (REE) is an ongoing study as the state of the art exploration like e.g. in China leads to a significant impact to the environment in terms of water pollution, destruction of the biosphere and erosion. For a mining project in Madagascar it is therefore...
In the mixed-dimensional representation of fractured media, the fractures are considered as lower-dimensional manifolds. This concept is successively applied to the lines and points at the intersections between fractures leading to a hierarchical geometry of manifolds of codimension one. By imposing these modelling assumptions a priori in the continuous setting, a basis is formed for the...
Fluid flow and heat transfer characteristics in packed beds are an important area of study with many applications in industry including design of catalytic beds and thermal heat storage units. Understanding of fluid flow and heat transfer at the pore scale is lacking due to the difficulty obtaining velocity and energy transport measurements in opaque systems. The use of macro scale...
A high order method is formulated for solving the miscible displacement problem and modeling viscous fingering. Viscous fingering in porous media may occur when a fluid with low viscosity is used to displace a fluid with high viscosity. For this type of flow instability, a tiny perturbation can be amplified exponentially, which triggers a finger-like pattern in the fluid concentration profile...
Microbially Induced Calcite Precipitation (MICP) is a bio-mediated soil improvement process that can improve the engineering properties of granular soils through the precipitation of calcium carbonate on soil particle surfaces and contacts. Although bio-cementation has been investigated extensively in laboratory experiments (DeJong et al. 2006, Martinez et al. 2013, and others) and...
Non-overlapping domain decomposition multiscale methods have been succesfully applied to flows in porous media. Such remarkable class of methods seek to decompose the domain of the porous media flow equations in non-overlapping subdomains, solving smaller local problems in parallel, and one global interface problem, instead of a large coupled one. Usually the interface problem enforces the...
In this presentation, we discuss enriched Galerkin (EG) algorithms for modeling Darcy flow, reactive transport, and elastic wave propagation. This approach involves enriching the continuous Galerkin finite element method with discontinuous elements. For transport EG is coupled with entropy residual stabilization for transport. The method provides locally and globally conservative fluxes,...
Numerical investigations of subsurface flow in fractured porous media provide information about properties connected to underground matter and heat transport just as characteristics of fluid underground storage capacity. Many diffusion-based models in the literature precisely describe subsurface flow. Nevertheless, pronounced hydro-mechanically-coupled phenomena like inverse water level...
Microbially-induced calcite precipitation (MICP) is being widely researched as an emerging technology for subsurface engineering applications including sealing defects in wellbore cement and modifying the permeability of rock formations [1]. Our study team, including Montana State University’s Energy Research Institute and Center for Biofilm Engineering, The University of Stuttgart, Montana...
The clearance of the metabolic waste in the body is handled by the lymphatic system. Except in the brain, which appears to be the only organ devoid of lymphatic channels. Indeed, the mechanisms underlying the clearance processes of the brain are still unknown, and the topic sparks debate and controversy. What is clear however, is that dysfunction of cerebral metabolic waste clearance is...
Multi-scale nature is one of the key features in complexity of rock structures from unconventional resources. Advanced imaging techniques such as high resolution Computed Tomography (CT) and Focused Ion Beam–Scanning Electron Microscopy (FIB-SEM) have shown that these low permeability rocks possess bi-model pores distribution. To characterize the inter-particle and intra-particle pores and...
Nuclear magnetic resonance (NMR) allows for non-invasive measurement of the dynamics of liquids in complex porous structures. In high-field NMR, measurement of restricted molecular motion and changes in magnetic relaxation times can characterize pore size and connectivity. Molecular diffusion measurements are utilized to identify the restricted motion of water after ingress into the pore...
We consider a shale gas reservoir with multimodal distribution composed of networks of natural and hydraulic fractures along with nano and micropores dispersed within the organic and inorganic matters.
Under the long term pseudo-steady state regime, characterized by the absence of pressure variability in the matrix, mass transfer between matrix and fractures can be approximated by the...
Understanding root water uptake is indispensable for the optimization of plant growth and crop yield against the background of growing world population. One strategy to understand how root water uptake functions is the knowledge of water flow from bulk soil to the root, passing the root-soil interface: the bottleneck for water uptake. Whereas direct flow imaging of fluxes in the above-ground...
The accurate high-order approximation in space and time is of fundamental importance for the simulation of dynamic poroelastic models which include coupled fluid flow, deformation and wave propagation.
Dynamic poroelastic models appear for example Lithium-ion battery fast-charge simulations and include sharp concentration and pressure gradients, high mechanical stresses, elastic wave...
Pore-scale flow modeling based on pore network model is an efficient simulation method. However, the distribution of two-phase fluid in pores and throats is based on the two-phase numerical simulation results in a single channel during the simulation of two-phase flow. The influence of pore-throat topology and pore-throat ratio cannot be considered. Hence, a new pore doublet model is proposed,...
Fluid storage in the subsurface is important to reduce climate change (sequestration of CO2) or for energy storage (CH4, H2) to cope with the intermittent, unpredictable production of renewable sources like wind and solar. However, the fluids have the potential to leak through damaged cap rocks or wellbores. One method to remediate these problems is inducing calcium carbonate precipitation...
We are interested in the numerical approximation of partial differential equations of elliptic nature, in the context of incompressible two-phase flow problems in heterogeneous porous media. Numerical solutions of elliptic boundary value problems with high contrast and discontinuous coefficients are often expensive and time consuming, so efficient numerical methods are necessary. Indeed,...
In mechanized tunneling, grouting mortars are necessary for the backfilling of the annular gap, which is the cavity between the surrounding soil and the lining segments. An adequate grouting mortar should ensure a force-fitting connection in order to minimize surface settlements above the tunnel lining. The specific application prescribes two contrary requirements towards the rheology of the...
The interior of living cells can be considered as a porous medium consisting of three compartments: cytosol, chloroplasts and mitochondria. Diffusion and reactions take place inside the cytosol, inside the chloroplasts and on the surfaces of the mitochondria. Furthermore, biochemical species can be exchanged between the compartments. Consequently we need to solve a system of fully dimensional...
We present a general model concept and a flexible software framework for the description of plant-scale soil-root interaction processes including the essential fluid mechanical processes in the vadose zone. The model is developed in the framework of non-isothermal, multi-phase, multi-component flow and transport in porous media. The software is an extension of the open-source porous media flow...
Strontium-90 (Sr-90), a toxic and carcinogenic radionuclide, is the product of uranium fission and is found in soil and groundwater at numerous DOE sites.1 Sr can also enter the environment through mine tailings leachate, produced water ponds (oil and gas extraction) or can occur naturally in rock formations.
A potential technology for groundwater remediation is the use of subsurface...
In subsurface characterization using a history matching algorithm, we reconstruct the subsurface properties, such as distributions of permeability and porosity, with a set of limited data. As a history matching algorithm, Markov chain Monte Carlo (McMC) method is effective for reconstructing permeability and porosity fields. The McMC method is serial in nature due to its Markov property....
We propose a new formulation based on discontinuous Galerkin (DG) methods in their generalization to polytopic grids for the simulation of flows in fractured porous media. The method that we propose is very flexible from the geometrical point of view, being able to handle meshes made of arbitrarily shaped elements, with edges/faces that may be in arbitrary number (potentially unlimited) and...
19F magnetic resonance has become a popular method in the medical field for quantifying oxygenation in blood, tissues, and tumors. The technique, called 19F NMR oximetry, exploits the strong affinity of molecular oxygen for liquid fluorocarbon phases, and the resulting strong linear dependence of 19F spin-lattice relaxation rate R1 on local oxygen concentration. The success of 19F NMR oximetry...
Diffuse interface methods are popular methods for modeling two-phase flow at the pore scale. These methods are based on the minimization of Helmholtz free energy of the fluid system and approximate the interface between the phases by a transition region of finite thickness. The mathematical model is a coupled system of time-dependent Cahn-Hilliard and Navier-Stokes equations. Contact angle...
The nanoscale flow characteristics are studied more and more popular recently, especially on the development of shale gas reservoir, and gas transport mechanisms include continuous flow, slip flow, and transition flow, which are complicated problems to study. Herein, experiments on deionized water and gas flow through micro-tubes and nanotubes with diameter of 16μm, 6μm, 124nm and 67nm are...
Newly developed weak Galerkin (WG) finite element methods will be introduced for solving partial differential equations on polygonal mesh.
The weak Galerkin method is a natural extension of the standard Galerkin finite element method for the function with discontinuity where classical derivatives are substituted by weakly defined derivatives. Therefore, the weak Galerkin methods have the...
We have given experimental grounding for the remarkable observation made 30 years ago by Furuberg et al. [1] of an unusual dynamic scaling for the pair correlation function $N(r,t)$ during the slow drainage of a porous medium. The authors of that paper have used an invasion percolation algorithm to show numerically that the probability of invasion of a pore at a distance $r$ away and after a...
Low-field nuclear magnetic resonance (NMR) is a non-invasive measuring technique and an excellent tool for determining properties of materials with high magnetic susceptibilities such as rock cores and natural sediments. NMR is sensitive to parameters such as pore size, pore fluid changes, and permeability that are of interest to engineering applications such as subsurface fracture sealing and...
Hierarchical network structures occur in many biological systems, since they are responsible for the transport of fluids, nutrients or oxygen. Such a network structure is, for example, the blood vessel network supplying organs with oxygenated blood or removing metabolic waste from the tissue. A further example is the root network of a plant, ensuring the plant‘s water supply.
One way to...
In data assimilation problems, various types of data are naturally linked to different spatial scales (e.g. seismic and electromagnetic data), and these scales are usually not coincident to the subsurface simulation model scale. Alternatives like down/upscaling [1] of the data and/or the simulation model can be used, but with potential loss of important information. To address this issue, a...
Standard models for flows in porous media assume that quantities like saturation, phase pressure differences, or relative permeability are related by monotone, algebraic relationships. These relationships are determined experimentally, assuming that the involved quantities have reached a local equilibrium. Under such assumptions, the solutions of the resulting mathematical models have...
NMR cryoporometry, relaxometry and diffusiometry are widely used for the characterization of porous materials.[1,2,3] In this work we investigated resorcinol-formaldehyde (RF) based carbon aerogels, prepared in different ways, with all the three NMR techniques parallel in aqueous medium. This made possible the comprehensive characterization of the aerogels concerning pore size and shape, pore...
With the advancement of multistage hydraulic fracturing technology, hydrocarbon production from tight reservoirs has exploded recently. Owing to its widespread nanopore, the permeability of tight sandstones are typically ~4 orders of magnitude smaller than conventional formations, thus leading to the breakdown of Darcy’s law within the complex nanoporous matrix. However, most of the existing...
Discrete fracture network (DFN) models explicitly use fracture geometry and network topology to simulate flow and transport through fractured systems. Recent advances in high performance computing have opened the door for flow and transport simulations in large explicit three-dimensional DFN. However, this increase in model fidelity and network size comes at a huge computational cost because...
We present a general implicit weighted essentially non-oscillatory (iWENO) method for solving advection-diffusion equations that is locally conservative and third order accurate, simple to implement, and allows general computational meshes. The scheme is quite robust, since it is unconditionally stable for smooth solutions to linear problems in 1D. The scheme requires only two unknowns per...
An Algebraic Dynamic Multilevel (ADM) method [1, 2] for fully implicit simulations of multiphase flow in heterogeneous fractured natural porous media is presented. The fine-scale fully-implicit (FIM) system is obtained following the Embedded Discrete Fracture Modelling (EDFM) [3] approach. A set of nested coarse grids at different resolutions (or levels) is constructed independently for each...
With fresh water becoming scarcer, especially in developing countries, there is a tendency to use sea water for making concrete. Hence, more information on the effect of Na and Cl ions needed on the hydration. During the hydration both types of ions can be chemically bound to cement components, as hydrates are being formed [e.g., Friedel’s salt Ca2Al(OH)6Cl2H2O]. Especially free chloride ions...
In the exploration of deep formations, alterations in pore pressure change the mechanical equilibrium of the porous medium leading to stress modifications which alter rock properties such as permeability and porosity and, consequently, the fluid flow pattern (Murad et al., 2013). The coupling of geomechanical effects and fluid flows is widely influenced by the natural rock heterogeneity...
We study experimentally and numerically drainage situation in a disordered porous medium. We show how the fractal dimension associated to capillary fingering, the Bond number and fluctuations amplitude in capillary thresholds allow to compute the residual saturation under various gravitational fields, and in various disordered distributions for the capillary thresholds. We also show how these...
Several biochemical processes have been investigated to modify engineering properties of soil. Biomineral precipitation can increase strength and stiffness, and reduce porosity and permeability. Enzymatically induced calcium carbonate precipitation (EICP) is a biochemical process in which urea is hydrolyzed into ammonium and inorganic carbon, which promotes carbonate mineral precipitation....
The organic and inorganic pores exhibit significant differences in pore sizes and surface chemistries that give rise to complex fluid flow behaviours. It is well known that pore size and pore connectivity directly impacts on macroscopic flow properties of a porous medium. Therefore characterization of strong heterogeneous shales with multiscale pore size is indispensable to accurately assess...
Plant tissues have developed several strategies to cope with multiple cycles of freezing and thawing events without being damaged. Some of these strategies are of physiological nature, others arise from structural properties. Understanding the involved strategies and mechanisms of plants exposed to frost conditions is of high interest, as they could potentially be used for the development of...
One of the most challenging issues in computational poromechanics is the development of numerical schemes capable of capturing in an accurate fashion the effects of spatial variability in the formation properties by handling highly heterogeneous coefficients with complex spatial distributions while preserving local conservation properties. In this work we present a new higher order...
Modelling flows within faults is crucial for various applications such as the control of faults on overpressure development or hydrocarbon migration
in sedimentary basins, the recovery of hydrocarbon components, subsurface gas storage, and
the appraisal of the risk of groundwater contamination following an underground nuclear waste disposal.
Faults can be characterized as extended...
A knowledge of fluid saturation at any one cross-section is very often required when studying fluid behaviour in porous media. It becomes more challenging in case of micro-scale geometry with heterogeneous morphology, as in complex geological samples. Our research effort in solving the challenge has led to a novel solution. We named this new saturation measurement identification approach,...
Numerical simulations of immiscible two-phase flow in porous
media with dynamic capillary pressure and gravity interactions in
heterogeneous porous media are presented with a novel computational
method based on ideas introduced in [1]. We formulate and test
numerically a new two-dimensional fully coupled and implicit procedure
for numericaly solving two-phase transport problems...
Microbially driven calcite precipitation (via ureolysis) has shown great potential in a wide range of applications, including solid-phase capture, concrete crack remediation, soil stabilisation and carbon sequestration. Here, this process is investigated as a means of reducing the primary porosity and/or secondary fracture porosity of host rocks surrounding nuclear waste repositories in order...
Once lung-cancer cells have invaded the brain tissue via the blood-vessel system, the cells proliferate and migrate in the tissue. The nutrients in the interstitial fluid ensure the proliferation and the basal reactions of the cancer cells. Over time, the cancer cells proliferate and form metastases. In experiments, multicellular lung-cancer spheroids are grown under fully-nutrient-supplied...
When a more viscous fluid displaces a less viscous one in porous media, viscous pressure drop stabilizes the displacement front against capillary pressure fluctuation. For this favorable viscous ratio conditions, previous studies focused on the front instability under slow flow conditions but did not address competing effects of wettability and flow rate. Here we study how this competition...
Rock typing is an essential step in reservoir characterization and geological model building for reservoir simulation. Conventionally porosity, permeability and capillary pressure data of coring core samples are used to divide rock types. With developing of high-resolution imaging equipment, micro-structure parameters are able to be quantified and wildly used in the research of reservoir...
The ISECG aims to realize the Mars manned space exploration mission in the 2030s. Since the duration of the Mars mission is assumed to be three years, a big concern is how to supply food for astronauts during the mission. The realization of space agriculture may be a solution for food supply problems in space. Understanding a moisture behavior in porous media under various small gravity...
When a solvent carries cations through a soil with fixed capacity for adsorption or ion exchange, the evolution of concentration fronts, which propagate through the soil at characteristic fractions of the solvent flow speed, is well described by classical theory. When the soil contains hydrophilic minerals such as iron oxyhydroxide, quartz, and clays which readily adsorb and desorb protons,...
We characterize the deformations of a dry granular medium confined inside a horizontal Hele-Shaw cell where air is injected at a constant overpressure. The overpressure is systematically varied, and we show a range of flow regimes where for example the injected fluid form channel structures similar to viscous fingers in a porous medium. By combining experimental deformation data and numerical...
Low frequency lattice vibrations (<100 cm-2) are indicators of variety of structural transformations in the metal-organic frameworks (MOFs) [1]. In the case of zeolitic imidazole frameworks (ZIFs) ZIF-4, ZIF-7 and ZIF-8, the terahertz vibrations which are responsible for such phenomena as gate opening mechanism, shear-induced deformations or breathing. ZIFs are promising materials not only for...
In several applications, morphology evolves over time, e.g. in the formation of pores in porous polymer membranes or in the formation of porous particles during spray polymerization of suspensions in a drying chamber. For example, during the preparation of porous polymer membranes by phase inversion process, a homogeneous polymer solution phase separates at contact with a coagulation bath due...
We present a mathematical model of flow and solid mechanics in saturated fractured porous media based on the Biot poroelasticity. The fractures are treated as lower-dimensional manifolds on which the system of equations is projected onto the tangent space and coupled to the surrounding through interface conditions. The model can describe porous fractures, fractures filled only by a liquid and...
The liquid-blocking effect occurs as the reservoir pressure drops below the dew point, which could increase liquid saturation, decrease flow efficiency and relative permeability, further leading to a sharp decline in production. Gas-wetting alteration has been an effective measure to enhance oil and gas recovery by improving flow efficiency in the blocking area. In this paper, we reported a...
Experiments on confined two-phase flow systems, involving air and a dense suspension, have revealed highly non -trivial flow morphologies. As the air displaces the suspension, the grains that make up the suspension tend to accumulate along the interface, and can build up force chains that jam the accumulated region. This dynamics will generate...
Recently, a new theoretical framework to describe 2-phase flow in porous media has been put forward by our research group. Within this theory, a transport equation for the wetting phase saturation can be derived. In order to utilize this new theory a constitutive relation is needed that characterizes the “mixing” of the two fluids. Here mixing is understood not as mixing on a molecular level,...
In this study, the drying behavior for a variety of calcium alumina- and hydratable alumina-bonded refractory castables was investigated in the temperature regime of first-drying, i.e., up to 300 oC. Using a specialized high-temperature Nuclear Magnetic Resonance (NMR) setup, we were able to directly and non-destructively measure the spatially and temporally resolved moisture distribution,...
Hydraulic fracturing (or fracking) is a well stimulation technique for unconventional oil and gas extraction [1]. Around 8-38 million cubic meters of fracking fluid containing water, chemicals, and sand are injected into the shale every day [2]. High-pressure injection of fracking fluids allows to create fractures and mobilize the gas and the oil towards the surface. Together with the gas, a...
Highly non-linear, porous structures stand out by significant changes of their morphology, allowing to control, e.g., their size, shape and acoustic band gaps. A research area that still remains to be fully explored in this exciting class of functional materials is their interaction with pore fluids. For example, the local-flow phenomenon is well studied for rocks, describing a local exchange...
We consider in this work, the extension to two-phase Darcy flows of the discontinuous pressure models in which the (d-1)-dimensional flow in the fractures is coupled with the d-dimensional flow in the matrix.The model accounts accurately for gravity effects inside the fractures, for discontinuous capillary pressure curves at the matrix fracture (mf) interfaces and for both drains and barriers....
Stress-dependent permeability and capillary force play important roles in determination of flow characteristics in fractures.Traditional empirical equations for relative permeability cannot accurately reflect transport behavior in rough fractures in consideration of normal deformation. In this paper, a systematic approach has been proposed to determine flow properties, such as relative...
Gas hydrates are crystalline solids formed when water molecules form a cage-like structure and trap a large number of gas molecules within. Gas hydrates are thermodynamically stable under conditions of low temperature and high pressure and occur in nature typically in permafrost regions and marine off-shores. If warmed or depressurized, hydrates destabilize and dissociate into water and...
Metal wire mesh is used in a wide variety of filtration applications. The geometric pore size is the diameter of the largest spherical bead that can pass through such a mesh. It is a very important quality measure and is found by filtering spherical glass beads with the mesh. Here, we describe how the geometric pore size of a mesh can be reproduced by computer simulations with GeoDict. The...
Surface charge at solid-electrolyte interface is generally affected by the local physical and chemical properties in the solution such as ionic strength, pH and so on. In a system with concentration or pH variation, rather than the prevailing assumption of homogeneous surface change, it leads to a spontaneous inhomogeneous distribution of surface charge, which has been observed in geotechnical...
Laboratory measurements, i.e. gas (N$_2$) porosity and permeability, time-domain nuclear magnetic resonance (NMR) including transverse relaxation time (T$_2$) and diffusion coefficient, and thin section and scanning electron microscopy (SEM) analysis, were conducted to obtain petrographical and petrophysical descriptions of the Weber Sandstone and Madison Limestone at the Rock Spring Uplift, a...
The physical processes governing flow and transport in porous media span a wide array of spatial scales. Furthermore, in many applications it would be computationally intractable to resolve each scale of interest. To still capture the effects of the smaller-scale processes, one option is to couple together models of different dimensionality. In e.g. vascularized tissue and root networks, the...
The use of energized fluids in hydraulic fracturing helps minimize formation damage and enhance well productivity especially in water sensitive reservoirs. Many current fracking simulators use single phase and incompressible flow assumptions to model the fracturing fluids. The thermal and compositional effects of using energized fluids on fracture topology are neglected by such simulators.
A...
Owing to huge proved reserves and successful application of stimulation technology such as fracturing, unconventional resources attract of worldwide attention. The study on fluid transportation in shale is rare for lack of powerful theory and models. Our paper focus on oil behavior in kerogen using methods combining MD simulation and NS equation. And an analytical mathematical model is derived...
Surfactant flooding is one of the mechanisms used to enhance oil recovery from oil reservoirs. Surfactants mainly reduce interfacial tension, increase oil mobility thus allowing better displacement of oil by injected water. One of the main challenges in this process is the loss of surfactant due to adsorption on reservoir rocks. The first adsorbed layer of surfactant is mostly governed by...
There are two main roles for the fractures in the gas reservoir development. On the one hand, fractures will improve the permeability of the reservoir, and the gas recovery of the high permeability reservoir will be higher than that of the low permeability under the same abandonment gas production rate. On the other hand, the water will rush along the fractures and the gas-water two phases...
We are concerned with the application of nonoverlapping domain decomposition methods on reduced fracture models. We provide for this problem a new DD algorithm in which the global problem is reduced to a mortar problem posed on the fractures that is solved by an iterative solver. Classical iterative methods are based on the CG or optimized Schwarz waveform methods which require...
It is well known that the radionuclide-carrying colloids in ground water can facilitate the transport of contaminants in the subsurface. A set of column experiments under physically and chemically heterogeneous conditions was conducted. Pore velocity was maintained below 100 cm/d and solution of CsI and silica colloids (1 micron diameter) was injected through saturated columns. At the same...
Department of Mechanical and Aeronautical Engineering, Clarkson University, Potsdam, New York, United States
An instability analysis of Poiseuille flow of concentrated suspensions in a channel is studied. The Poiseuille flow with two layers where both dilute and concentrated suspensions flow is overlaid by a soft porous media is considered for the analysis. The Brinkmann equation together...
In the formulation of multiscale methods for second order elliptic equations that are based on domain decomposition procedures, (see e.g. the Multiscale Mortar Mixed Finite Element Method (MMMFEM) [1], the Multiscale Mixed Method (MuMM) [2], Multiscale Robin Coupled (MRC) [3], the Multiscale Hybrid - Mixed Finite Element Method (MHM) [4]) typically the computational domain is decomposed into...
Geological storage of CO2 in subsurface saline aquifers is a promising way to reduce CO2 emissions. During this process, CO2 first dissolves into pure brine, forming an acidic and denser mixture that falls down under the gravity and reacts with the rock [1, 2]. From the fundamental science point of view, the above process is indeed flow and reactive transport processes in porous...
Physicians often face multiple possible strategies treating a specific disease and it is crucial to have a predictive numerical methodology that can help with selection of the best option. Brain aneurysms are a result of a weakened blood vessel wall that, if not treated well, can have a lethal rupture. To prevent the rupture, multiple devices are available, including coils and flow diverters....
Natural gas hydrate is ice-like crystal compound formed by water and natural gas molecules under certain temperature and pressure, which widely distributed in terrestrial permafrost and deep sea sediments. Natural gas hydrate as the most promising development clean energy, can effectively solve the energy crisis and environment pollution problems [1]. Nowadays, the microscopic distribution...
In this work, we show an alternative way of handling the spatially discontinuous capillary pressure models in two-phase flow in porous media. This topic is very challenging and has also been studied theoretically and numerically in recent works [1,2,3]. We propose a new numerical formulation, by combining mixed hybrid finite element and finite volume discretization strategies along with novel...
Up scaling techniques allowing to use coarser meshes have rigorous fundations as well as the underlying heterogeneous porous medium presents some statistical homogeneity. In that situation, homogenization theory works well and provides closure problems, the solution of which gives rises to up scaled paramters. These assumptions break down in presence of a front corresponding for example to...
The storage and seepage of oil and gas in the reservoirs are controlled by pore size distribution, pore shape, pore throat and connectivity. Pore structure is of vital use for understanding and evaluating the storage and seepage properties of low-permeability reservoir. Fractal theory is considered as an effective method to describe the heterogeneity of pore structure.
Numerous models have...
In this work, we present a parallel MPI software, called GENFIELD, to generate stationary Gaussian random fields, based on the circulant embedding method [7, 1, 4].
The advantage of the circulant embedding method over existing methods (Cholesky factorization of the covariance matrix, Karhunen Loève series expansion) is its computational efficiency. It relies on Discrete Fourier Transform that...
A lattice Boltzmann method is applied for investigating the flow and convection diffusion processes in porous media with fractures and vugs at representative elementary volume (REV) scale. The structural parameters of porous media at pore scale are introduced into the generalized lattice Boltzmann equation (GLBE) to describe the relationship between permeability and porosity. A two-dimensional...
This paper introduces an original application of the hypercomplex numbers known as Quaternions to model non-isothermal processes in porous rocks. The general thermoporoelastic linear theory is introduced in four dimensions and reformulated as a set of quaternions. The need of the fourth dimension appears naturally because of the pores presence. It is shown that a minimum set of four...
Unconventional reservoirs like shale or tight reservoirs were usually characterized by its multiscale and unequally distributed pore system, the microporous fabric of unconventional porous media in nanometer size range can cause complex transport mechanisms. For developing a better understanding of flow property in unconventional reservoirs with strong heterogeneity, a new upscaling method...
Zeolites have great potential in adsorption and separation of alkanes-olefins mixtures with similar properties due to its shape selectivity and huge specific surface area1. In our work, a series of zeolites were quickly screened to separate 1-chloropropane from 1-chloropropane/allyl chloride gas mixtures by the molecular simulation. The adsorption isotherm curves of simple component were...
Enriched Galerkin (EG) methods were defined in 2009. The idea is to use a variational form arising from a discontinuous Galerkin (DG) method, but instead of using discontinuous approximating spaces, one uses a continuous space enriched with piecewise discontinuous constants. EG has fewer degrees of freedom than DG, and so is easier to solve, but it maintains the local conservation property of...
This work has been motivated by the study of solid tumor growth, and more specifically, by the examination of the most frequently encountered type of pediatric primary bone tumors (osteosarcoma), characterised in their early stage by the formation of non-mineralised bone tissue, called osteoid [1]. As the tumor evolves in time, mineralisation of this growing tissue can take place.The objective...
The metallic foams are a novel possibility to impact significantly the design of materials taking into account the wide technological applications [1,2]. In this work the procedure to manufacture metallic foams with controlled porosity is presented. A high pressure cell is used to submit the metallic foams to reservoir conditions, which imply high pressures and high temperatures. The injection...
The Radial Basis Function generated Finite Differential (RBF-FD) is a meshless method that has attracted attention in the last decades by its flexibility in the numerical approximation of PDEs, simplicity of computational implementation and ease in the approach of complex geometries. It has already been successfully applied to various engineering problems such as heat transfer, electrostatics,...
In this talk, the speakers will introduce a high order flux-conservative finite element method for the fluid flow model equations in porous media. The numerical schemes are based on the classical Galerkin finite element method enhanced by a flux approximation on the boundary of a prescribed set of control volumes. The numerical approximations can be characterized as the solution of a...
In this talk, experimental results of structural stability of synthetic rocks and metal foams[1] subjected to reservoir conditions are presented. By controlling the injection of water and mineral oils ona confinement cell, the samples are subjected to conditions of high pressure (25KPSI) and high temperature (200°C). By means of micrography techniques the mechanical deformation of foam layers...
With developments and applications of micro-reactors in the food, chemical and pharmaceutical industry, hydrodynamics and transport processes of drops in shear and extensional flows in micro-channels have attracted much attention from both academics and practitioners. Such systems specifically demonstrate potentials to enhance transport in micro-channels. The objective of this work is to...
Weighted essentially non-oscillatory (WENO) schemes can be used to solve the equations governing transport in porous media. They are also useful in defining slope limiters for discontinuous Galerkin and other finite volume or finite difference methods. WENO reconstructions are a weighted average of polynomial approximations defined on various grid stencils. They are designed to produce high...
Naturally Fractured Reservoirs (NFR) are usually multiscale in nature and exhibit power law length distributions which do not possess any characteristic length scale, rendering the use of continuum methods such as the dual porosity model invalid due to the non-existence of Representative Elementary Volumes (REV) (Berkowitz, 2002). This necessitates the adoption of hybrid models that represent...
In this presentation we present a numerical method for simulating fluid flow in highly anisotropic and heterogeneous porous media. To understand the behavior of the fluids at the scale of applications (the macro scale), the flow at the scale of pores (the micro scale) needs to be taken into account. In this case, standard numerical methods will either fail or become inefficient due to the...
As an unconventional gas resource, coalbed methane (CBM) reservoir has unique flow mechanism and production scheme compared with conventional and other unconventional gas reservoirs. The permeability of coal cleats system varies with the production of water and gas, in order to accurately forecast gas productivity, the dynamic permeability model should be investigated first before establishing...
We consider a porous medium where the pore space is completely filled by three different phases: two immiscible fluids like water and air or oil and a solid phase. The non-wetting phase contains no solute and has no interaction with the solid phase. The wetting phase contains dissolved ions, which can precipitate at the pore boundary to form the solid phase. The reverse process of dissolution,...
Atomic level simulations, such as molecular dynamics (MD), Monte Carlo (MC) or DFT, have recently become indispensable tools for characterization of porous materials [1]. Computational methods are often used to study adsorption, diffusion or separation mechanisms. Here, we perform density functional theory (DFT) calculations of structural properties of flexible and rigid nanoporous MOFs. For...
To establish and maintain well integrity to avoid leakage through wells is vital for production wells relevant for the petroleum industry, and for injection wells used for CO2 sequestration. To ensure that stored CO2 remains underground in a long-term perspective it is of the utmost importance to optimize the integrity of both active and abandoned wells. The properties of well barriers such as...
Extracting connected micro-fractures from 3D XRT images of carbonate and shale core samples is critically important to perform numerical fluid transport simulation in porous media, but difficult to honour their true connectivity because they are often distorted by noises, artefacts and the complex intersections among the fractures to appear disconnected in the imagery. These challenges can be...
This study describes wettability alteration mechanism of calcite surface by low salinity water (diluted seawater) and ion tuned water (regarding to potential determining ions, PDI). The contact angles of brine droplets on calcite surfaces that immersed in oil were measured. The relative ability in modifying the surface wettability of these three ion species (Ca2+, Mg2+ and SO42- ions) thus is...
Abstract
Transport of charged species in porous media is significantly affected by the electrochemical migration term resulting from charge-induced interactions among dissolved ions. Such electrostatic interactions during multicomponent ionic transport have been investigated both in diffusion-dominated systems [1-3] and, recently, in advection-dominated systems for steady-state plumes...
The microstructure of a radioactive waste confinement barrier strongly determines its flow and transport properties. Numerical flow and transport simulations for these porous media at the pore-scale are necessary for in-depth understanding of the pore-scale processes, and might for instance allow making predictions beyond current experimental timescales. Such simulations of course require...
Abstract
Immiscible two-phase flow in porous media is a process encountered in various applications such as oil recovery, soil remediation, CO2 sequestration and some other industrial systems. Almost all models of two-phase flow are based on Darcy law, which is valid only for the phases that form a continuous domain. But, there exist many applications where one of the fluid phases is...
In their seminal works, Taylor and Bretherton showed that when a wetting viscous liquid is displaced by a less viscous non-wetting fluid in a capillary tube, a film of the defending liquid is left on the walls. Here, we revisit this classic problem in the partial wetting regime using both experiments and theory, and show that the flow dynamics drastically changes from the classic picture. We...
The frozen food products are subjected to freeze-thaw cycles during storage and shipping. These cycles result in ice recrystallization, surface dehydration, and solute and moisture diffusion, which damage the foods quality. The re-crystallization phenomena involves multiscale characteristics spanning from the scale of polymers to macroscale. The transport of moisture and vapors is complicated...
The competition between different driving forces (pressure gradients, gravity, internal friction, etc.) typically leads to various instabilities together with the development of a wide range of visually impacting patterns. The particular case of frictional flows, which consists in the displacement and structuring of a granular phase under viscous or capillary stress, can be considered as a...
Bayesian seismic inversion can be used to sample from the posterior distribution of the velocity field, thus allowing for uncertainty quantification. However, traditional Markov chain Monte Carlo (McMC) can be extremely computationally expensive. In this presentation we compare recently proposed, computationally effective McMC methods, such as a two-stage [1,2], a Hamiltonian procedure [3],...
Subsurface systems are well known to have variations in wettability. Evolving models to describe such systems must be evaluated and validated, and highly resolved experimental observations can play a central role in this endeavor. Quantities such as interfacial areas and curvatures are examples of quantities that are not often measured in high resolution as a function of wettability. ...
In this work a methodology is presented for modeling a fractured porous media and to simulate oil recovery by low salinity water injection through a fractured core. To represent the porous matrix a continuum approach is employed whereas for the fractures a discrete one. Thus, the fractured core is modeled with mixed dimensions elements, representing the fractures as elements of n−1 dimensions...
Research in geotechnical applications of artificial ground freezing is important task in maintaining the stability of engineering structures in permafrost. Safe design require a correct prediction of the coupled thermo-mechanical behavior of soils. Mathematical model of process of thermal stabilization (artificial freezing) on the classical Stefan model is built.
A feature of the modeling of...
Elastic moduli are amongst the most important parameters to assess the shale plays and to instruct the hydraulic fracturing. However, due to extremely high brittleness of shale and very limited samples available, the conventional methods to obtain elastic properties, for instance, uni-axial or tri-axial compression tests, often encounter with early breaking apart of shale samples, which leaves...
An experimental observation of the structuring of a granular suspension under the progress of a gas/liquid meniscus in a narrow tube is reported here. The granular material is moved and compactifies as a growing accumulation front. The frictional interaction with the confining walls increases until the pore capillary entry pressure is reached. The gas then penetrates the clogged granular...
Due to the existence of electric double layer in fluid-saturated porous media, Acoustoelectric effect will occurred when acoustic waves propagate through media. In the logging while drilling environment the drilling collar might be taken as a shear source. SH-TE acoustoelectric logging is a potential method to obtaining shear wave velocity directed in LWD environments. When the interface exist...
A water infiltration rate into soil or porous media is reported to be slower in microgravity than on the earth with 1G (Jones and Or, 1999) as well as for hydrophobic soils (DeBano, 1971). Water characteristic curves under the microgravity condition (Heinse et al., 2007) and for hydrophobic soils (Bauters et al., 2000) very much look alike little changes in matric potential with various water...
Heat conduction in porous materials is of great interest for geological and engineering studies including geothermal reservoirs, insulating layers, composite materials, to name a few. In the absence of flow, thermal energy is transferred through the constituting materials of porous media with different capabilities in conducting heat. Thus, the structure of phase boundaries, the contact area...
Many technical materials, biological tissues and living cells are ionized porous media. Under changes of osmotic boundary conditions, these ionized gels respond by swelling to many times their own volume. As the macromolecular network of the gels has limited strength, fracture propagation may occur. Modelling of 3D finite swelling and subsequent fracture requires very careful modelling....
Several biological processes have been developed in the recent years in which the hydro-mechanical soil properties can be modified by precipitating calcium carbonate. Microbial and enzyme induced carbonate precipitation (MICP and EICP) have gained interest in potential biological processes to improve the mechanical properties of the soil by precipitating calcium carbonate, which forms...
In this study, slip flow of gases were measured in several tight reservoir rock samples and nanofluidic chips. The results were then compared to gas flow simulations by DSBGK. Klinkenberg permeability of rocks was obtained using a steady-state method under varying pore pressures but constant temperature and effective stress. Experiments conducted in nanofluidics devices, which have controlled...
A technique for studying flow in porous media at the lab scale has been previously developed in our laboratory. The technique involves a confined miniature cylindrical geometry that is obtained by heating and pulling on a 100ml cylindrical capillary. The narrow region of the capillary, tapered and cylindrical, is filled with cryolite to form a random, porous medium, and two-liquid-phase-flow...
Controlling fluid flow through permeable and fractured media is important in a variety of subsurface contexts including geologic carbon storage (GCS). Low pH and or high salinity conditions create corrosive aqueous environments which would rapidly degrade cement in wellbores or carbonate/clay features in caprocks. Our group has explored the potential to deploy dissolution/precipitation...
Abstract: Eight gas-water relative permeability curves of natural ultra-low permeability cores were tested from a new steady experiment at eight different permeability levels. The absolute permeability is the gas permeability at irreducible water saturation. The results show that the curve have displayed a very sharp decrease in gas relative permeability while a slow increase in water relative...
Treatment of water for human consumption often involves filtration through reactive porous media, such as activated carbon, or metal oxides. The sorption of contaminants inevitably leads to a depletion of available free sites and therefore a decrease in efficiency. A possible technique to regenerate filtration systems is the use of chelation agents. Such compounds, i.e. ...
The progress of the interface between an invasive fluid and a defending mixture of granular material together with a second fluid, immiscible with the invading phase, has recently been used to form complex patterns in both Hele-Shaw cells or millifluidic confinements. These are the result of the deformation of a confined porous material, made of an homogeneous granular phase, into an...
State of the art multi-dimensional nuclear magnetic resonance (NMR) relaxometry and diffusometry techniques along with magnetic resonance imaging (MRI) are applied to explore and characterize phase change in complex systems. High-field NMR techniques are highly sensitive to the thermodynamic phase of the system as well as restrictions on molecular motion. High resolution imaging along with...
Digital Rock Physics (DRP) has made many useful results in the petrophysics (Saenger et al., 2011). Because of the contradiction between resolution and rock size, DRP can't effectively study the law and mechanism of the impact of macroscopic factors on petrophysical properties of complex reservoir such as sonic, resistivity characteristics. Meanwhile, reservoir rocks are usually highly...
With the increasing demand for enhancing production of oil and gas all over the world, improving oil recovery technologies aiming at developing low permeable and tight oil reservoirs are becoming the focus of current research. To help understanding the mechanism of multiphase displacement in underground reservoir, the microcosmic characterization of porous media must be explored. In recent...
Separate Sensible and Latent Cooling (SSLC) systems have considerably improved performance compared to single vapor compression based system for moisture management in buildings. Such systems often deploy solid desiccant based dehumidifier to absorb the excess moisture from air streams. The steady state and transient characteristic of desiccant materials (micro, meso or nano porous structures)...
Because of the low permeability of shale, fractures typically act as the primary flow conduits in these formations. It is therefore imperative to understand the fundamental processes that influence fracture properties in shale to accurately predict unconventional resource production as well as ensure sequestered CO2 does not migrate out of a storage reservoir. In this study, a novel shearing...
The clearance of the metabolic waste in the body is handled by the lymphatic system. Except in the brain, which appears to be the only organ devoid of lymphatic channels. Indeed, the mechanisms underlying the clearance processes of the brain are still unknown, and the topic sparks debate and controversy. What is clear however, is that dysfunction of cerebral metabolic waste clearance is...
In this work, we have performed an efficient implementation of
the multiscale mixed method MuMM introduced in [1], that is based on a
non-overlapping iterative domain decomposition procedure with novel Robin
interface conditions (see also [2] where the variational formulation of [1]
was presented). We also performed a numerical study to built multiscale
mixed basis functions to find an...
The shale of the lower Silurian Longmaxi widely develops in Changning area of Sichuan basin. In order to study the micro pore structure and pore size distribution characteristics of shale reservoirs in this area. The pore structure of lower Longmaxi shale gas formation is researched by field emission scanning electron microscope (FE-SEM), high pressure Hg injection, low temperature nitrogen...
Relaxometric imaging has already been known in MRI of natural porous media and plants for some decades. Mostly T2 maps are determined due to the relatively short measurement time. However, T2 is often accelerated by diffusion processes in internal gradients caused by the high magnetic field strengths typically encountered in MRI. Therefore, the information can not be unambiguously assigned to...
The purpose of this work is to build a coupled geomechanics-flow model to accurately simulate the in-situ stress and fluid flow in fractured reservoir. The model is developed by iteratively coupling a geomechanics model that uses the Continuum Damage Mechanics as its basis to investigate relationships between fracture dynamic change and pore pressure vary. The coupled model also reveals some...
Application of flow and transport simulators for prediction of the release, entrapment, and persistence of dense non-aqueous phase liquids (DNAPLs) and associated contaminant plumes is a computationally intensive process that requires specification of a large number of material properties and hydrologic/chemical parameters. Given its computational burden, this direct simulation approach is...
The physical processes governing flow and transport in porous media span a wide array of spatial scales. Furthermore, in many applications it would be computationally intractable to resolve each scale of interest. To still capture the effects of the smaller-scale processes, one option is to couple together models of different dimensionality. In e.g. vascularized tissue and root networks, the...
The two-phase flow study is meaningful for mass transfer in various industrial processes, for example the prediction of proppant distribution is of significance due to the fact that proppant placement contributes to the enhanced production of fluids by affecting the conductivity of the fractured reservoir. Since it is difficult and expensive for experiments to consider various conditions and...
In geological carbon storage, understanding main mechanisms affecting migration and redistribution of injected CO2 in aquifers is needed for developing predictive models to assess post injection environmental risks and designing long term monitoring schemes. This work presents experimental and modeling studies to investigate processes contributing to post-injection CO2 plume distribution and...
A three-dimensional (3D) high resolution inner structure of rock sample is premise for pore-scale flow simulation of reservoir. µ-CT is considered to be the most direct way to obtain the 3D inner structure of porous media without deconstruction. However, its micrometer resolution limits its application in characterization of small structures such as nano-pores and channels which are critical...
In view of the present situation of low productivity and the difficulty of water injection development in the tight reservoir. In order to improve the development effect of tight reservoir, select cores with different permeability grade parallel samples, and carried out injection of simulated formation water, active water, CO2 and N2 physical simulation experiment. Combined with nuclear...
The Richards equation is a commonly used model for unsaturated flow through porous media. Using the Darcy law in the mass balance equation, and bringing the resulting equation to a dimensionless form one obtains:
\begin{equation}
\phi\partial_t S=\nabla\cdot\left(\frac{K}{\mu} k_r(S)\nabla (p -\rho g z)\right)+f(S,\vec{x}).
\end{equation}
Here $\phi$ is the porosity of the medium; $z$ is the...
At present, many methods of porous media modeling have been proposed. Among them, the multiple-point statistics (MPS) method has a unique advantage in reconstructing 3D digital rock in that it can characterize long-range connectivity of pore space. The Single Normal Equation Simulation (SNESIM) is one of most commonly used algorithms of MPS. In the SNESIM algorithm, the selection of training...
In order to improve the field productivity, the industries can create new fractured wells to reduce the interval between the initial fractures. However, the production from the initial fractured wells can induce stress reorientation in the vicinity of the fractures. As such, a refracturing treatment in the stress reorientation region can lead to a reoriented refracture which has a more or less...
As one of the most important energy resources, improving the recovery of tight gas reservoir will be great significance. However, the complicated pore structure and special fluid flow mechanism makes it difficult to study with usual experiment methods. To address this problem, a systematic experiment procedure is proposed and applied to Sulige tight gas field. First, the pore structure is...
The shale gas flowing in the Nano-scale pore structure in shale formation has the properties of over scale and over flow region. It is difficult to describe the flow pattern by using the conventional flow theory. In this study, a physical modeling test of depletion development and the flowing model of gas flow in the micro-nano pores of shale matrix were studied. Through the pore size testing,...
In the process of thermal recovery and the underground storage of nuclear waste, the porosity and permeability of rock will change significantly from thermal stress. In this paper, a sandstone sample was subjected to heating, porosity examination, permeability measurements and CT scanning. Based on digital core technology, permeability and thermal conduction simulations were performed. The...
Results of high-resolution particle velocimetry (PIV) measurements are presented to explore how the turbulent flow overlying a permeable wall is linked to the underlying pore flow and how their interplay is controlled by the topography of the wall interface and by the wall thickness. Two permeable walls were constructed from uniform spherical elements (25.4-mm diameter) in a cubically packed...
Adsorption is one of the most important ways of coalbed methane stored in the coal seam. Methane diffusion in coal plays an important role in coalbed methane production. Understanding the characteristics of adsorption and diffusion of coalbed methane is keys to correctly evaluate the gas content and effectively enhance the gas production. As well known, most coal seams contain a certain amount...
Soil liquefaction is a significant natural hazard associated with earthquakes. Some of its devastating effects include tilting and sinking of buildings and bridges, and destruction of pipelines. Conventional geotechnical engineering assumes liquefaction occurs via elevated pore pressure. This assumption guides construction for seismically hazardous locations, yet evidence suggests that...
The interest in developing microbial induced carbonate precipitation as a cement alternative in oil and gas wells stems from the fact that this biotechnology can penetrate pore networks that conventional cement grouts cannot due to their high viscosity. Currently MICP is under investigation as a potential wellbore barrier technology to mitigate hydrocarbon leakage through a) micro-channels in...
The cleat or natural fracture system is a dominant factor controlling the permeability of coal seams. Gas permeability and porosity of coal samples with artificially generated fractures are measured under varying effective stress. Based on the experimental results and the Walsh model, fracture width and roughness are estimated. Considering the fracture aperture and roughness, we present a 3D...
The transport of electrolytes in porous media is affected by physical, chemical and electrochemical processes. Coulombic interactions significantly influence the behavior of electrolyte plumes at different scales, not only in diffusion-dominated conditions but also in advection-dominated flow regimes [1-3]. To model the spatial behavior of charge-induced interactions in multi-dimensional...
Due to the size effect of nanochannels and the strong influence of nanochannel surfaces, these ultra-confined water and oil molecules behave extraordinary differently from their bulk counterpart. Therefore, it is of great necessary to study the adsorption and transport of water and oil molecules in the nanochannel.
In this paper, we investigate the adsorption and transport mechanism of...
Shale reservoirs generally have very low porosity and permeability and complex occurrence and transport state, which lead to its unique L-curve production characteristics, representing complicated flow mechanism. A physical experiment using full diameter core was designed to simulate the full lifecycle development process of the shale gas well. From the experiment, many important and...
Due to intense complexity and heterogeneity of pore and throat structure in tight formation, it’s very difficult for representation. In addition, as there abounds in large numbers of micro-nano pores and throats, boundary layer and media deformation effect on pore scale flow cannot be ignored. Therfore, an accurately representative pore network flow model which couples boundary layer and media...
A three-dimensional lattice Boltzmann model (LBM) is used to predict fracture permeability. The LBM is first verified by comparing the predicted permeability of a straight pipe with a rectangular cross section with the analytical solution. Excellent agreement is achieved for various aspect ratios of the cross section. Then the LBM is used to simulate single phase fluid flow in fractures whose...
Fractured geological formations are ubiquitous throughout the world, and their stress-sensitive behaviors are of primary interest in a number of contexts. In this study, a stress sensitivity experiment on carbonate core plugs in which micron Computed Tomography (μ-CT) technology is applied to visualize and quantitatively evaluate morphological changes to the fracture aperture with respect to...
Abstract: To research the influence of interfacial tension of fracturing fluid on spontaneous imbibiton in low-permeability water-wet reservoir, a spontaneous imbibition model was constructed upon a modified LW imbibition model includes hydrostatic pressure and flow resistance with fractal theory, and the relationship between spontaneous imbibition volume and imbibition time was described by...
The geologic sequestration of CO2 is a potential solution for decreasing anthropogenic atmospheric CO2 emissions by trapping it underground. A primary mechanism for storage is structural trapping where low permeability and high capillary entry pressure caprock materials hold back the buoyant CO2 from rising to the surface. The wettability (or contact angle) of reservoir and caprock materials...
Highlights
1. Intracrystalline diffusivities of olefins were estimated by SV (Solid Vibrational) model.
2. Effective vibrational frequencies are calculated by curvature of potential well.
3. Selectivity of propylene in both catalysts increases with temperature.
4. Ethylene to propylene diffusivity ratio obtained in ZSM-5 is 2.3 while in SAPO-34 is 35.6.
Abstract
Light olefins...
We study a simple model for the transport of polymer particles injected along with water in a porous rock containing oil. The main goal of this technique is to recover oil that remains trapped after waterflood. Such enhancement occurs through a microscopic diversion of the water flow caused by clogging of narrow pore throats by the injected particles. The diverted flow may lead to the...
Porous interfaces are encountered across a broad range of length scales, both in natural and engineering flow systems. Understanding the coupling between the free flow and the pore flow is key to accurately predicting many important biogeochemical processes occurring in such systems. This is particularly true when the free flow is turbulent and the coupling involves an intermediate region...
Subsurface fluid injection is a proposed method for the storage of hydrocarbon fuels and the mitigation of fossil fuel emissions. Concerns about leakage exist when storing fluids in the subsurface given their potential to damage functional groundwater aquifers or be emitted to the atmosphere. Defects detrimental to the integrity of subsurface storage systems can occur in and around the...
Choosing an appropriate modelling approach for fluid flow and stress field interaction in rocks belongs to the key problems within the context of several subsurface applications such as geothermal power generation, disposal of waste water, CO$_2$ storage or hydraulic fracturing. A central issue in this respect is the question of whether the equations for flow and geomechanics are solved in a...
The spatial distribution of physical and chemical heterogeneities is critical in many subsurface applications. For instance, the location of reactive minerals is a primary factor controlling the fate and transport of organic and inorganic pollutants in groundwater. A number of studies have focused on using hydrologic measurements and inverse modeling techniques to image physical heterogeneity...
In this study, the detail flow of ink though the printing paper is simulated using pore-scale formulations. The exact 3D topology of an uncoated paper was obtained though micro-tomography imaging to reconstruct the domain with a resolution of 0.9 µm. Afterwards, the reconstructed domain was used for running direct numerical simulation of ink flow in paper. Confocal microscopy was applied to...
Studying the phase behavior of complex hydrocarbon and hydrocarbon/CO2 mixtures in kerogen structures is extremely important for understanding the mechanisms involved in enhanced gas recovery, storage, and production of hydrocarbons from shale. The objective of this work is to determine the phase behavior of a number of binary, ternary, and multicomponent CO2/hydrocarbon systems using...
Drying in porous media is of interest to many research and engineering fields, such as recovery of volatile hydrocarbons from underground oil reservoirs, remediation of contaminant soils by vapor extraction, and water management in gas diffusion layers (GDLs) of proton exchange membrane fuel cells (PEMFCs).
The drying process in a porous material is dependent on the structure and wettability...
In this talk, we are concerned with the computational analysis of saturation overshoots for two-phase flow in porous media. In particular, it is of interest under which conditions a given saturation overshoot remains stable, while moving through a porous medium. In order to investigate this issue, we consider a decoupled and a fully coupled model, where drainage and imbibition processes are...
In this talk we will introduce a one-domain approach based on the Brinkman model for the modeling and simulation of the transport phenomenon between free fluid and a porous medium. A thin transition layer is introduced between the free fluid region and the porous media region, across which the porosity and permeability undergo a rapid but continuous change. We study the behavior of the...
In this work, we perform multiscale modeling of gas transport through the heterogeneous solid having irregular pore structure and contrast of properties on different spatial scales. We assume that the solid consists of inorganic material (clay, sand) with organic (kegogen) inclusions imbedded into it. There exist a contrast of properties and spatial scales between the matrix and inclusions....
Hydraulic fracturing is a subsurface stimulation technology that has been deployed at a massive scale in North America, and made it possible to produce hydrocarbons from low-permeability rocks, like oil shales and gas shales, which traditionally had been considered uneconomical. Despite this large-scale deployment, our understanding of the physics and controlling parameters in hydraulic...
The Richards equation is a commonly used model for unsaturated flow through porous media. Using the Darcy law in the mass balance equation, and bringing the resulting equation to a dimensionless form, for gravity driven flow one gets the equation:
\begin{equation}
\partial_t S(p)= \nabla \cdot \left[ k(S) \left( N_c \nabla p - 1\right)\right].
\end{equation}
Here $N_c$ is the capillary...
Paper curl due to wetting and drying is known to be determined by the degree of fiber swelling, the paper structure and material inner tensions from the paper production process which are released due to wetting. Apart from these well documented processes we have found that the development of paper curl is govererned by different mechanisms depending on the observed time domain.
Our...
Understanding the nature of solute transport in the subsurface is important for applications such as CO2 storage in deep saline aquifers and the extraction of oil and gas from deep sandstone or carbonate formations. However, limited knowledge exists in this area due to the extent of heterogeneity in geological formations and the additional complexity coming from presence of multiple fluid...
Abstract
Porous asphalt pavements are often used to reduce runoff and improve the highway security. As a result, water may be retained in the internal pore structure of porous asphalt roads. The ability of asphalt material to dry after exposure to water may affect its functionality and durability thus it is important to understand water evaporation process from asphalt.
We have conducted...
Small-scale heterogeneity of permeability plays a major role in the spreading and mixing of contaminant plumes in groundwater systems. Spreading and mixing are interrelated because heterogeneity-induced spreading leads to the stretching of interfaces of the contaminant plume, while mixing across the interfaces is governed by local hydrodynamic dispersion. In many practical problems, mixing is...
Spontaneous imbibition is an important recovery mechanism in naturally fractured reservoirs as capillary forces control the movement of fluid between matrix and fracture. Imbibition is also important in unconventional reservoirs as the capillary pressure will increase when permeability decreases, impacting fracture fluid imbibition during the fracturing process but also during the soaking...
Although droplet spreading on smooth surfaces is well known, spreading on
textile materials is still not fully understood. Compared to a solid surface, on
textile the liquid can penetrate the holes in the fabric but also spontaneously flow through the porous networks inside the fabric (wicking), making droplet
spreading more complex compared to smooth surfaces. Understanding...
One of the innovative application of cellulose fibers is the desalination of masonry structures in the field of architectural heritage conservation [1]. Wet poultices, classically composed of cellulose fibers and clays, are coated on the porous material to be treated, and kept in place before being removed when dry. The efficiency of the process partly depends on the drying behavior of the...
Proper descriptions of heterogeneity are essential for understanding and modeling single phase (e.g. contaminant transport, saltwater intrusion) and multiphase (e.g. geologic carbon storage, enhanced oil recovery) transport problems from the sub-core scale to reservoir scale. Application of medical imaging to experimentally quantify these processes has led to significant progress in...
Reactivation of fractures is a strongly coupled problem involving disparate
physical processes such as fluid flow, temperature and rock deformation. We present a coupled mixed dimensional model, where the main focus is on the deformation of fractures. We will discuss numerical solutions of friction models for the reactivation of pre-existing fracture networks, and the treatment of the...
Accurate characterization of the multiscale pore structure in carbonates reservoirs is a complex but crucial step for pore-scale modelling of the corresponding flow and transport properties. 3D images obtained using micro computed tomography (CT) are only able to capture a relatively narrow range of pore sizes at a given resolution and fail to reproduce cross-scale pore connections. Therefore,...
We investigate pore scale drainage associated with immiscible displacement of brine by CO$_{2}$ in a porous medium, using state-of-the-art multi-GPU lattice Boltzmann (LB) simulations. Our goal is to better understand the pore scale processes involved in the geological sequestration of CO$_{2}$. Correctly resolving the pore scale dynamics of multiphase flow in permeable media is of paramount...
Several mathematical models with various degrees of complexity and accuracy have been developed to describe the dynamics of drying porous media. At the effective medium scale, a continuum approximation is used and the transport phenomena are described by a set of partial differential equations [1]. While classical and extremely useful, and in spite of many studies, the continuum models (CMs)...
Tingyu Lia, Dongxu Hanb, Bo Yub, Dongliang Sunb, Fusheng Yanga, Jinjia Weia
a School of Chemical Engineering and Technology, Xi’an Jiaotong University, Xi’an 710049, China
b School of Mechanical Engineering, Beijing Institute of Petrochemical Technology, Beijing 102617, China
Corresponding authors: E-mail addresses: yubobox@vip.163.com (B.Yu).
As the most effective method for mining deep...
One of the main mechanisms to immobilize CO2 during geological carbon sequestration is residual trapping as a result of capillary forces at the pore-scale. It is often assumed that in the capillary dominated regime, capillary equilibrium within the system is reached instantaneously. This approximation is valid for homogeneous systems where the largest scale of heterogeneity is at the pore...
In many applications such as geothermal energy, geological carbon sequestration, unconventional gas recovery, and injection induced seismicity (IIS), there is a need to model flow and transport phenomena in fractured rock. In fractured rock, the hydraulic and mechanical properties of the fractures are extremely sensitive to fluid pressure and other perturbations. Although the general problem...
Hydrocarbon sorption in unconventional formations accounts for a significant amount of gas in place depending on rock mineralogy and organic content. Traditionally, sorption amount experiments have been performed on powders or crushed porous solids that ignore changes in pore structure.
Dilatometry experiments, however, show that changes of volume during sorption can result in dramatic...
The typical characteristic of a thin porous layer is that its thickness is much smaller than its in-plane dimensions. A stack of thin porous layers creates contact interfaces, whose properties are quite different with thin layers. Determining the hydraulic properties is essential to understand and model fluid flow in thin porous media. The validity of classical methods in thin porous media is...
The inkjet technology fuels the rapidly evolving world of printing. This printing technology delivers good print quality using the flexibility of digital printing at a breakthrough cost price. The R&D department of Océ Technologies, a Canon company, is a major player in the development of inkjet technologies for many different applications.
Liquid spreading, evaporation and imbibition into...
Two approaches based on Lagrangian statistics of turbulent flow in porous media are investigated. In the first approach, usage of Lagrangian coherent structures (LCS) to understand barriers in transport and mixing in turbulent flows is studied. The computation of LCS typically involves post processing of experimentally or numerically obtained fluid velocity fields to obtain the finite time...
Pome fruit such as apple are harvested mature but unripe, stored at low temperature (typically -1.0 to 3°C) in combination with a reduced O2 and increased CO2 partial pressure in so-called controlled Atmosphere (CA) storage. This is done to delay climacteric ripening, and, hence, extend their storage life. The optimal storage gas composition is critical, as too low O2 levels in combination...
Pore-scale water content controls the function of soil microbial communities by modulating the hydraulic connectivity of microbial communities and the flux of aqueous and gaseous substrates. In turn, soil bacteria regulate local moisture within porous structure through the secretion of extracellular polymeric substances (EPS). EPS promotes water retention as hydrogel in several ways: (i) by...
Carbon-fiber papers (CFPs) are an integral component of many energy-conversion and energy-storage technologies, including gas diffusion layers (GDLs) in polymer electrolyte membrane fuel cells (PEM fuel cells), cathode GDL in PEM electrolyzers and metal-air batteries, and as electrodes in redox flow batteries (RFBs). CFPs must fulfill several functions such as providing adequate mechanical...
During the post-injection and stabilization period of geological carbon sequestration, the primary forces governing CO2 migration and entrapment are capillarity and buoyancy, delineating a specific field of application for numerical flow models. In contrast with conventional modeling approaches that assume laminar viscous flow regime, a modified invasion percolation (MIP) simulator is used to...
CO2 sequestration in subsurface often suffers from poor volumetric sweep efficiency due to low gas viscosity, low gas density, and formation heterogeneity. This study aims to investigate CO2 mobility control techniques of Water Alternating Gas (WAG) and Surfactant (or Nanoparticle) Alternating Gas (SAG) to increase CO2 storage capacity in Cranfield Field, Mississippi via field-scale...
Understanding fault reactivation as a result of subsurface fluid injection is critical in geologic CO2 sequestration (and other geo-energy applications such as wastewater injection) because it may result in enhanced fault permeability, potentially inducing CO2 leakage from the injection zone through the overlying caprock. Faults display a complex architecture characterized by a low...
The fact that examining Eulerian entities in unsteady velocity fields gives misleading information on Lagrangian coherence is now well-established. In this talk, I will review a range of techniques which have been proposed to extract coherent structures from given velocity data. These include the commonly used finite-time Lyapunov exponents, as well as methods such as curves/surfaces to...
Fractures act as dominant pathways for fluid flow in low-permeability rocks. However, in many subsurface environments, fluid rock reactions can lead to mineral precipitation, which alters fracture surface geometry and reduces fracture permeability. In natural fractures, surface mineralogy and roughness are often heterogeneous, leading to variations in both velocity and reactive surface area....
Recently, the accurate and efficient modeling of flow-structure interactions has gained more importance and attention for both petroleum and environmental engineering applications. Three main coupling approaches exist in practice: the fully implicit, the explicit or loose coupling, and the iterative coupling methods. The first approach solves the two problems simultaneously, and is considered...
Oil-water emulsion injection has shown significant potential as an Enhanced Oil Recovery (EOR) method. Experimental results revealed that drop size, drop concentration and local capillary number as the most relevant parameters affecting emulsion performance as water phase mobility control agent.
Emulsion injection in real reservoirs and production predictions requires a deep understanding of...
Incorporating sub-metre scale capillary pressure heterogeneity into upscaled numerical models is key to the successful prediction of low flow potential plume migration and trapping at the field scale. At low flow potential, nearing the capillary limit, the upscaled equivalent relative permeability incorporating capillary pressure heterogeneity is far from that derived at the viscous limit [1],...
Subsurface scalar transport of e.g. heat or chemicals by fluid flow is key to problems as enhanced oil recovery, enhanced geothermal systems, carbon sequestration or in situ minerals mining. The Lagrangian transport properties of the subsurface flow are crucial in such processes. For example, recent studies in the literature on a two-dimensional (2D) unsteady Darcy flow in a circular reservoir...
Injection-induced seismicity (IIS) depends on pore pressure, in-situ stress state, and fault orientation; generally occurs in basement rock that contains fractures and faults; and moves away from the injection well as a nonlinear diffusion process. Therefore to numerically model IIS, a code should incorporate coupled flow and geomechanics, the presence of fractures and faults, and the...
Understanding fluid flow and deformation processes in thin swelling porous media is critical for developing superior consumer absorbent hygiene products such as wipes, paper towels, feminine pads and diapers [1-4]. Fluid-flow models have proven very valuable for the development of these products and have led to the development of fundamental understandings in transport mechanisms, numerical...
The presented work deals with polymer injection in an oil reservoir of which the geological organization is obtained thanks to an outcrop located close to the Ainsa town in southern Pyrenees, Spain. In this study the permeability distributions are not fixed. We address the following question: what is the impact of permeability distribution on the oil recovery considering a polymer slug...
In this work we develop an a posteriori-steered algorithm for a two phase compositional flow with exchange of components between the phases in porous media. The discretization of our model is based on a backward Euler scheme in time and a finite volume scheme in space. The phase transition is treated introducing a formulation based on Henry's law. The resulting nonlinear system is solved via...
Fracture network can be commonly found or produced in many natural or damageable porous media, such as reservoirs, brittle materials and soil. Thus, fracture network and fractured porous media as well as their transport properties have received great attentions in many fields. Fractures are usually extended in length and aperture to form complex fracture network under some external conditions....
Understanding the factors that control CO2 convective dissolution, which is one of the permanent trapping mechanisms, in the deep saline aquifer and associated dynamics of mixing is crucial in the long-term fate of the injected CO2. The present study investigates the effects of temporal changes in the solubility of CO2 at the free-phase CO2/brine interface on the onset of natural convection...
Formaldehyde is a very important chemical with a wide range of applications. Methanol partial oxidation on Fe-MoO3 catalyst is the most favorable method for formaldehyde production. The catalyst for this process is highly selective toward formaldehyde production (selectivity > 90%). Methanol conversion in the process is also high (conversion > 98%). The scholarly work on methanol partial...
Membrane filters have been widely used in industrial applications to remove contaminants and undesired impurities from the solvent. During the filtration process the membrane internal void area becomes fouled with impurities and as a consequence the filter performance deteriorates, which indeed depends on filter internal structure, particles concentration and flow. The complexity of membrane...
Natural rock fracture networks exhibit complex, multiscaling relationships for fracture length, transmissivity, orientation, density and network connectivity. Of these properties, network connectivity has remained more of an abstractive construct than an easily definable parameter. The degree of network connectivity in fractured rocks profoundly impacts movement and retention of solutes. We...
In this project we aim to measure flow velocities in porous media. We demonstrate our method in a rectangular flow channel, for which a semi-analytical solution of the flow field exists. The flow channel is made of borosilicate glass and its refractive index is matched with the fluid. Upon doping of the fluid with microspheres, those particles can be tracked to reveal the velocity field of the...
Modeling and simulation of multiphase flow and transport in underground porous media is an essential component in many scientific and engineering applications. Now, more and more focus has been paid on the Diffuse Interface models, which describes the interface as a continuum three-dimensional entity separating the two bulk single phase fluids.
Realistic equation of state (e.g. Peng-Robinson...
The simulation of flows in poro-fractured heterogeneous media is a challenging task, manly as a consequence of the geometrical complexity of the domain. Fractures in the porous matrix are dimensionally reduced to co-dimensional interfaces, in order to avoid the resolution of the scale of the fracture thickness, which can be orders of magnitude smaller than the typical dimensions of the...
Permeability is one of the most important petrophysical parameters for reservoir characterization, completion design and production prediction, etc. However, due to the strong heterogeneity, poor pore structure, extremely low porosity and complicated minerals types in shale gas reservoirs, it is challenges for estimating the permeability accurately.
In this paper, we present a method for...
ABSTRACT
Two-phase flow in porous media is a process encountered in various applications such as oil recovery, soil remediation, CO2 sequestration and many other industrial systems. Multiphase flow in porous has been experimentally investigated with the use of micro-models, as well as natural porous media. Up to now, fluid pressure measurements during two-phase flow experiments in...
Grand canonical Monte Carlo and molecular dynamics simulations were applied to understand the molecular mechanism of species transport in clays. The variation of clay basal spacing as a function of relative humidity predicted based on the swelling free energy profiles was consistent with X-ray data. The hydration of clays shows the following well-known order: Mg2+ > Ca2+ > Sr2+ > Li+ > Na+ >...
The phenomenon of pressure generation and relaxation inside a porous media is widely observed in biological systems. For example, the pressurization inside the cartilage plays the key in the load bearing and lubrication of the knee joints. In this paper, we report a biomimetic study to examine the transient pressure distribution inside a soft porous layer when a spherical loaded surface...
We start from the description of unsaturated flow in porous media with the
Richards' equations. This model uses pressure and saturation as unknown variables, they satisfy one parabolic equation and one algebraic relation. The Richards' equations provide a useful model in many situations, but they fail dramatically in the explanation of one specific experiment: When a highly saturated medium...
The dissolution of supercritical CO2 in aquifer brine is one of the most important trapping mechanisms in CO2 geological storage. As supercritical CO2 is less dense than the ambient groundwater, the injected CO2 is susceptible to leakage in case that the sealing layer is not perfectly impermeable. However, when CO2 is dissolved in water it is not buoyant anymore. In fact, CO2-saturated water...
Textiles are porous media found in a wide variety of configurations, resulting from weaving, knitting or crocheting yarns into networks. Textiles consist of multiple scales of fiber, yarn, fabric and multilayered systems, each showing their own porosity system and complexity. Wicking, or the spontaneous liquid capillary uptake in the resulting multiscale pore system, needs a multiscale...
When dealing with poro-fractured media, performing efficient simulations of
physical phenomena such as the transport of contaminants, subsidence or com-
puting the hydraulic head distribution can be very challenging due to the high
number of possible geometrical configurations that have to be taken into ac-
count. Recently, the flexibility of the Virtual Element Method in dealing...
Mixing in the presence of convective instabilities in an homogeneous porous media is governed by the behavior of stagnation points where the fluid interface is stretched and compressed. It has been shown that an interface compression model is able to predict the behavior of the scalar dissipation rate. The mixing regimes experienced by these kind of systems are linked to the dependency of...
In this paper, we report a novel experimental study to examine the lubrication theory for highly compressible porous media (Feng & Weinbaum, JFM, 422, 282, 2000), which was applied to the frictionless motion of red cells over the endothelial surface layer (ESL). The experimental setup consists of a running conveyer belt covered with a soft porous sheet, and an upper planar board, i.e....
Multiphase flow in porous media is relevant to a range of applications in the energy and environmental sectors. Recently, the interest has been renewed by geological storage of CO$_2$ within saline aquifers. The coupled flow dynamics of CO$_2$ and brine in geologic media must be better understood, particularly at the pore scale, because pore-scale phenomena, such as Haines jumps and...
Understanding the dynamics of fluid flow and transport in porous media is important in several subsurface applications including geologic CO2 storage, hydrocarbon recovery, geothermal energy, and groundwater hydrology. In order to control and optimize said dynamics, it is imperative that these processes be considered at the pore (or micro) scale. Pore-scale models provide a useful means of...
Matrix acidizing is a stimulation technique that is extensively being employed by petroleum industry in carbonate reservoirs to improve permeability and enhance production [3]. The acidizing technique involves injecting acid to dissolve minerals in order to create long highly conductive channels known as wormholes. The wormhole formation is the optimal scenario in carbonate matrix acidizing....
We study the in situ measured distributions of contact angles and curvatures within mm-size X-ray tomography images of rock samples from a producing
hydrocarbon carbonate reservoir imaged after wateflooding [1]. We analyse
their spatial correlation on a pore-by-pore basis using automated methods for
measuring contact angles [2], a new method for measuring curvatures, and by
performing pore...
Flows in packed beds are encountered in many engineering applications, such as solar thermal energy storages, chemical catalytic reactors, petroleum and civil engineering, magnetic refrigerators, biological tissues, and pebble-bed nuclear reactors.
Critical challenge of designing packed beds involves understanding the total pressure loss, complex flow fields, heat and mass transfer...
Gravity-driven fingering is commonly observed during water infiltration in soil. An important feature of gravity fingering is the presence of saturation overshoot, which is understood to be a necessary prerequisite for gravity fingering in unsaturated flows. The Richards model in its basic form, along with the standard (monotonic) pressure-saturation relation, is incompatible with saturation...
Most commonly used numerical models of unsaturated porous media flow use a single capillary retention function which is specified at the start of the model run and alters capillary pressure only as a function of saturation. However, changes in porosity are common in geologic and industrial applications across a wide range of time scales. Consequently, numerical models of unsaturated media...
Modeling subsurface flow in three-dimensional (3D) discrete fracture networks (DFN) is of interest of many engineering problems, such as CO2 sequestration, natural gas production and geothermal energy extractions. However, the recent grid-based models describing flow behaviors in 3D DFN are still suffering from the complex gridding issue and high computational burden. In this work, a meshless...
In this paper, an efficient, totally decoupled and energy stable scheme is presented for the Cahn-Hilliard phase field model of two-phase incompressible flows. The rigorous proof of unconditional energy stability for the semi-implicit scheme and the fully discrete scheme are provided. The scalar auxiliary variable (SAV) approach is implemented to solve the Cahn-Hilliard equation while a...
In general, unsupervised machine learning (ML) methods are powerful tools for data analyses to extract essential features hidden in data. The integration of large datasets, powerful computational capabilities, and affordable data storage has resulted in the widespread use of ML in science, technology, and industry. Here we present applications of ML to characterize (1) reactive transport data...
The objective of this work is to use micromodels to investigate the feasibility of using viscous microemulsions to mobilize oil in fractured, oil-wet porous media by inducing crossflow. Production by water flooding from fractured oil-wet media, such as carbonates, is challenging because capillary forces prevent water imbibition into the matrix. Recently, experimental core floods (Parra et...
The flow behavior through porous media is yet to be fully understood. The comprehension of the fundamental physical mechanisms and of the dynamics can significantly help the development of many applications in the engineering field.
A porous system can be formed by natural as well as by artificial processes, and is mostly described by granular media, compacted under external forces. The pore...
Drying of porous media is of significant importance in many fields ranging from hydrology and agriculture, to industrial applications, e.g., food sciences and chemical engineering. The drying process depends on both the external atmospheric conditions and structure of the porous medium. Previous research has shown that hydrogel produced by plant seeds/roots or bacteria can change the physical...
Nanoparticle stabilized emulsions have attracted interest for enhanced oil recovery (EOR) because of their improved stability to coalescence over emulsions stabilized with surfactants. This behavior is due to the irreversible adsorption of nanoparticles to the oil/water interface which can inhibit droplet coalescence. However, characterization of nanoparticle stabilized emulsions for EOR has...
Acidizing is a commonly used stimulation treatment for carbonate reservoir by injecting acid into near-wellbore formation to remedy the damage and to create operational-optimal deep-penetrating and narrow high permeability channels, termed as wormholes, by mineral dissolution. Wormhole formation in un-fractured matrix has been widely studied by numerical modelling, but little work has been...
Capillary end effect develops in tight gas and shale formations near hydraulic fractures during flow back of the fracturing treatment water and extends into the natural gas production period. Previous studies showed the potential flow impairment mechanisms in tight gas and shale formations and discussed to a certain extent that they may influence a well’s performance during production....
Subsurface methane hydrates have long been regarded as a potential energy source to power the future. Significant research efforts have been dedicated towards the exploration of methane hydrate reserves around the world. This study is focused on quantifying the diagenetic changes that occur during and after the formation of methane hydrates in the subsurface. A 2-dimensional geological model...
In this study penetration and spreading of printing ink on paper in High Speed Inkjet (HSI) printing is investigated. Printing ink penetration is reducing color density and spreading of the ink on the surface is crucial for development of print density. Three measurement techniques are evaluated: Ultrasonic liquid penetration measurement (ULP), contact angle measurement (CA) and scanning...
The complex fluid-solid interactions and irregular crack patterns in hydraulic fracturing cause substantial numerical challenges, which can make conventional crack modeling methods ineffective. In the present work, a stabilized and nodally integrated meshfree formulation for hydro-mechanical modeling of crack propagation in saturated porous media is developed. Under the stabilized conforming...
Nowadays, ceramic materials are used in many industries. Ceramic materials are well known by their high strength and excellent thermal and chemical stability. In addition, most of ceramics retain acceptable mechanical properties at temperatures higher than 1000 C. However, the low impact toughness of these materials limits their use in industries such as aerospace. The porous nature of the...
Suspensions and their applications can be found in many fields of mechanical, civil and environmental engineering. The rheological behavior of suspensions strongly depends on the concentration of suspended particles. To consider the flow behavior as well as fluid-solid interactions in dilute suspensions, we present 3D Direct Numerical Simulations (DNS) of a single-phase fluid with discrete...
Future reservoir performance under reservoir uncertainty has been estimated conventionally by posterior model simulations followed by history matching of prior models to observed data. In the history matching step, however, more than hundreds of simulation runs may be required to calibrate prior model parameters such as facies, permeability, and porosity. To address the computational...
Micromodels have been widely used to study the transport mechanism of fluids at pore-scale for subsurface engineering applications such as enhanced oil recovery. Micromodels with small feature sizes can be manufactured by lithography-based microfabrication on Si or glass, but they are in general restricted to 2D representation of pore network geometry. Recently our group demonstrated more...
Geothermal is a kind of unconventional energy with abundant reserves. It owns the advantages of low carbon emissions, climate-free, widely distributed, and enormous mining potential. At present, the research on the development of hot dry rock (HDR) are mainly studied from the perspective of the macroscopic scale. However, due to the existence of natural fractures of different scales in real...
It is well known that naturally fractured reservoirs very often represent the behavior of dual porosity systems, however, it is also similarly known that simulating flow and transport of oil and gas through dual porosity systems is computationally expensive, especially if simulating enhanced oil recovery (EOR) processes. Most of the simulation work that is thus done for full field and/or...
One of the key issues related to long-term polymer electrolyte membrane (PEM) fuel cell durability is water management within the porous gas diffusion layer (GDL). When too much water accumulates within the GDL, the flow of the gases to the catalyst layer becomes restricted, which can lead to the degradation of key cell components or even result in total cell failure. Therefore, understanding...
Many subsurface operations – such as drilling, cementing, well completion, and production – can result in damage to the rock formation near the wellbore, decreasing the permeability and resulting in a reduction in oil or gas production. Acidizing is one type of treatment that is employed to increase the permeability around the wellbore. In carbonate rocks, acidizing can not only reduce the...
As actual CO2 injection is unlikely to take place at Kevin Dome, Montana, the Big Sky Carbon Sequestration Partnership has turned to maximizing the value of existing data acquired at the site. We present the risk assessment work done using the National Risk Assessment Partnership (NRAP) to Kevin Dome, Montana. Geologic CO2 sequestration in saline aquifers poses certain risks including...
During geologic CO2 sequestration, most of the storage domain far from the injection sites is likely to be dominated by buoyancy and capillary forces. Under such flow regimes, small scale geological heterogeneities have been shown to dampen plume migration rates and cause trapping beneath capillary barriers. To understand the impact of such heterogeneities on CO2 trapping processes...
CO2 storage in deep geologic formations is a necessary method to address the climate change problem. To ensure long-term security of the injected CO2, a better understanding of the post-injection CO2 residual trapping phenomena is needed. Using multiphase coreflooding experimental methods, we seek to characterize and predict the amount of CO2 residual trapping after injection.
Spatial...
Mass transport combined with heterogeneous reaction in homogeneous porous media is a common process encountered in chemical engineering that is of major concern for many applications ranging from packed bed reactors to porous electrodes. In these systems, reactants are transported by diffusion (and eventually by advection) inside the pores where chemical reactions take place at the solid-fluid...
Thermochemical materials can store solar energy in the form of chemical energy. The stored solar energy can be used for household applications (hot tap water and room heating). These materials thus form a so-called heat battery. We investigate how salt hydrates can be used for this purpose. These salt hydrates release water (dehydration) when they absorb solar energy in summer. They absorb...
Conventional two-phase flow equations (Richards Equation) for porous media at the macroscale require capillary pressure (Pc) and relative permeability (Kr) measured as a function of saturation (S). However, these equations lack solid theoretical foundation, and there is still a considerable gap between the theory and experiments. In typical experiments, an “average” macroscopic capillary...
Thermochemical heat storage has a large potential due to its high storage density. In the range of high to medium temperature heat storage the system Calciumoxide – Calciumhydroxide is of special interest, as it reacts at handable temperatures (300-500 °C), is environmentally friendly and financially attractive.
The following chemical reaction is considered:
$ \text{CaO}_s +...
Multimodal conglomerate rocks have complicated structure depending on the packing state and the relative proportions of sand and pebble-sized grains in the rock. The relation between porosity and permeability, and porosity and water saturation, in multimodal conglomerate rocks quite different from those common in clastic reservoirs having unimodal grain-size distributions. The characterization...
Thermal conduction in natural porous media has been deeply paid attention in science and engineering, for example, exploiting and utilizing the geothermal energy, determining the heat flow in hydrothermal systems, obtaining the information about the past climate, modelling the hydrocarbon formation processes and investigating the potential nuclear wastes, etc. The thermal conductivity plays an...
Building a three-dimensional (3D) porous medium is the basis of carrying out the numerical simulation of the fluid flow. To date, many techniques of constructing porous media have been proposed by scholars. Among them, the multiple-point statistics (MPS) method has a unique merit of reconstructing 3D digital rock because it can reproduce long-range connectivity of pore space. The Single Normal...
Earthquake mechanics relies on the ability to simulate frictional failure of faults. One of the dominant characteristics of seismic events is unstable frictional failure, that is, the occurrence of fast runaway slip.
In their seminar work, Dieterich [1] and Ruina [2] proposed a mathematical description of friction, the rate and state friction law, which is capable of reproducing stick-slip...
In order to understand the pore structures and fluid distribution in the oil reservoir rock which is a kind of porous media, X-ray computed tomography which can yield high-resolution, three-dimensional representations of pore space and fluid distribution within porous materials is applied to obtain data on structure, porosity, permeability, and other rock properties. Segmentation method of CT...
Compositional two-phase fluid flow in porous media, especially on geometrically complex domains, require high fidelity geometric discretization. Moreover, since multi-component multi-phase flow and transport in porous media usually come with strong nonlinearity and stiffness in multiple spatial and temporal scales, it is necessary to deploy a multi-scale approach that is inevitably...
Water injection has been potentially considered as an efficient method for supporting the pressure in most oil reservoirs. Novel EOR techniques such as smart water flooding have gained more attention referring to both the recent research activities and the falling of oil price. In spite of many attempts on acquiring the main responsible mechanisms of smart water flooding in many individual...
The Mishrif Formation in the Hafaya Oilfield is mainly characterized by porous carbonate reservoir with large marine biology, different sediments and complex diagenesis. Reservoir in this area has diverse pore types, poor correlation between porosity and permeability, poor well logging response and reservoir evaluation is difficult. The diagenetic patterns of different microfacies have been...
The reservoir heterogeneity of the restricted platform in the Mishrif formation of Iraq HF oil field is strong, different microfacies experience different diagenesis and pore evolution process, and the seepage characteristics are different. Therefore, to clarify the differential diagenesis and pore evolution mechanism is the basis of improving development effect. Based on core observation,...
A fundamental understanding of multiphase flows in porous media is relevant to enhanced oil recovery as well as to the process of CO2 sequestration in hydrocarbon reservoirs and saline aquifers. Recently, we quantified two-phase flow mechanisms in micromodels that represent the pore networks of natural complex porous media [1]. Using micro-Particle Image Velocimetry (micro-PIV), we are able to...
In this study, a discrete pore-scale model is developed to predict the drying characteristics of an aggregate composed of primary particles with a multimodal size distribution. The solid phase is represented by a cubic particle packing and the complementary pore space is constructed by using the pore-scale finite volume approach. The vapor forming as a result of (slow) evaporation escapes...
The objective of this paper is experimental measurement of CO2 diffusion coefficient in different nanofluids including (SiO2), aluminum oxide (Al2O3) and titanium oxide (TiO2) nanofluids. Nanofluids in concentrations of 0.05, 0.1 and 0.2 wt% were used in experiments. Different factors such as temperature, weight percentage of nanoparticles, as well as the effect of particle size were...
Although modeling transfers through naturally fractured media has been the subject of extensive investigation since the 1960's (Bear et al. 1993, Berkowitz 2002, Adler et al. 2012), it remains a challenging field of research. Applications range between management of polluted groundwater, nuclear waste storage (Fourno et al. 2004), CO2 sequestration (Verscheure et al., 2012), oil field...
Cold asphalt mixture (CAM) is a road materials obtained by mixing bitumen emulsion, aggregate, water and often cement at ambient temperature. When using CAM, aggregates and binder do not need to be heated during the mixing operation, which brings social, economic and environmental benefits compared to other paving materials, such as hot mix asphalt (HMA).
Like other types of asphalt...
In this study, we have developed a novel microfluidic high-pressure high-temperature vessel to house geomaterial (natural rock or mineral chips) micromodel specimens. Realistic fracture patterns were laser-scribed on the organic-rich shales of Draupne Formation, the primary caprock for the Smeaheia CO2 storage site (the full-scale CCS project) in Norway. The primary research objective was to...
The Bruggeman model is often used to calculate effective properties of batteries. Yet, the theory relies on a simplified representation of the pore-scale structure. Access to detailed topological information of battery electrodes by means of Tomography and Scanning Electron Microscope images provides new opportunities to more accurately estimate effective parameters. We propose a computational...
Batteries and pumped hydropower plants store solar energy in the form of chemical and mechanical energy. Another attractive option is storing energy in the form of heat. Probably the best-know example are the so-called heat pads that are used in outdoor activities. We investigate how to use sugar alcohols as heat batteries. Sugar alcohols are an abundant product of the food industry and they...
The use of gas-solid reactions for thermochemical energy storage has been widely discussed in literature. Still, the question of handling a reacting solid on a technically relevant scale is not solved yet: structural changes within the porous solid media need to be considered when designing high-power storage reactors for commercial applications.
In an experimental study, we have successfully...
Micromodels have been artificially manufactured with microfluidic networks of pores and throats, thus emulating the pore-scale geometries in porous media, for example, oil reservoir rocks. Micromodels manufactured in Si or glass have been used to visualize fluid flows in waterflooding experiments and two phase flow experiments, but their geometries have been limited to 2D pore network...
Across a wide range of flows, to date the Spatial Markov Model, a member of the continuous time random walk family of models, has had great success in predicting mean transport behavior - e.g. breakthrough curves and the temporal scaling of flow aligned spatial moments, but applications to modeling mixing and reactions have been more limited. This is because these are nonlinear in nature,...
Methane hydrate is a non-stoichiometric crystalline structure in which water molecules form hydrogen-bonded cages with methane molecules inside. Abundant methane hydrate resources are present on Earth, especially in various mineral porous media (e.g., permafrost and sea-floor).[1] Methane hydrate is important for many applications in the field of energy and environmental science.[2,3]...
In the framework of underground flow simulations in fractured media, modeled by Discrete Fracture Networks (DFNs), we focus on the issue of the non-deterministic description of the network. For performing numerical simulations, fractures are indeed typically sampled from probabilistic distributions for both hydro-geological properties (fracture transmissivity) and geometrical features...
The physical processes which determine the sessile droplet / porous paper interactions have been the subject of many studies in the last decades. Both theoretical understanding and sustainable industrial applications are the driving forces for these studies. Nowadays, inkjet is one of the main printing technologies, offering the flexibility of digital printing at a breakthrough cost price,...
Data has been described as the world’s new oil, as a resource with immense potential to inform and transform daily life as well as science and engineering. The volume of newly generated scientific data is projected to exceed 40,000 exabytes by 2020. At present, however, only 20% of the world’s data are preserved online. Field, lab, and computing datasets all contribute to an improved...
Evaporation from porous media is of great interest to many research and engineering fields, such as recovery of volatile hydrocarbons from underground oil reservoirs, remediation of contaminant soils by vapor extraction, and water management in gas diffusion layers (GLDs) of proton exchange membrane fuel cells (PEMFCs). During runnig of PEMFCs, produced water may condense and fill open pores...
Multiphase immiscible displacement in porous media is a process occurring in different applications, such as CO2 sequestration in saline aquifers and oil/gas production from hydrocarbon reservoirs. Capillary pressure, Pc, is one of the variables that controls flow behavior and displacement patterns that ultimately determines residual saturation. Capillary pressure is a function of...
Motivated by the process of convective mixing in porous media, here we study the pattern-formation and coarsening dynamics arising from dissolution of CO2 in a single-aqueous phase during three-dimensional (3D) Rayleigh-Benard-Darcy convection. Our focus is on comparing the pattern-formation aspects of solutal convection between conditions of constant concentration and constant flux...
Pressure-induced temperature transient analysis has emerged recently with the downhole temperature monitoring techniques to characterize the reservoir. In this work, we develop analytical approaches and solutions to model the temperature signals associated with variable rate production of slightly compressible fluid and apply it to several field temperature measurements to characterize the...
Acid fracturing is a stimulation technique that has been widely used in developing fractured-vuggy carbonate reservoirs. Wormholes and hydraulic fractures, which are created by this technique, form the main channels of the fluid flowing into the wellbore. Complex seepage systems near the wellbore pose significant challenges to study the transport process in these reservoirs. Based on the...
For further research on the effect of heavy oil viscosity on the fracture geometry, this paper establishes heavy oil fracturing model and conventional fracturing model based on thermal-hydraulic-mechanical (THM) coupled theory, Walther viscosity model and K-D-R temperature model. We take viscosity and density within heavy oil fracturing model as functions of pressure and temperature, while...
Gas transport in unsaturated fractured media plays an important role in applications such as shallow CO2 leakage from carbon sequestration sites, methane leaks from oil and gas operations, and remediation of volatile contaminant plumes. Driven primarily by barometric pumping, the time scale of relevant gas transport can vary from months or years to the order of days depending on a variety of...
An ultra-tight sealing caprock is essential for safe storage of CO2 in deep geological basins. One of the basic requirements of this shale sealing is to ensure it is free of faults/fractures or other high permeable zones that may lead to unintended leakage of CO2 from its storage reservoir to above zones. Sealing capability of caprock is typically characterized by permeability measurement of a...
In order to quantitatively describe the influence of the surface roughness of sandstone fracture on its seepage law, the three - dimensional fractal dimension D and three - dimensional surface height deviation Sa are used to characterize the surface roughness of sandstone fracture. Through the seepage test of sandstone specimen with different fracture surface roughness and different crack...
In this presentation, we report a novel experimental approach to investigate the compression-dependent Darcy permeability of soft porous media. Especially, we are proposing new correlations that describe the change of the permeability of random fibrous porous media as a function of its compression. A special device was developed that consisted of a rectangular flow channel with adjustable gap...
The three-dimensional version of the Virtual Element Method is a field under
great development, both from the theoretical point of view [1] and the im-
plementation aspects [2]. The simulation of the flow inside a poro-fractured
medium has been recently tackled using the Virtual Element Method in the
context of Discrete Fracture Networks [3–6]. Here we consider the threatment
of non...
In-depth understanding of fluid and solute transport through complex porous media is of significant importance in various engineering and scientific applications. Large-scale behaviour of fluid and solute transport are determined by pore-scale features. Therefore, it is crucial to determine pore-scale transport properties and then upscale these properties to large scales. Numerically...
Wettability is known to have an enormous impact on oil recovery in the petroleum industry and efforts are being made to assess the role of such conditions. This work creatively tailors the microchip surface wetting property by using rock-forming mineral coatings. The mineral surfaces are created in microchips by using the novel layer-by-layer (LbL) assembly technology.[1] The formed mineral...
Cohesive particle swarms have been shown experimentally to exhibit enhanced sedimentation in fractures for an optimal range of fracture apertures. In this optimal range, swarms travel farther and faster than a disperse (particulate) solution. This study aims to uncover the physics underlying enhanced sedimentation. Swarm behavior at low Reynolds number in a quiescent unbounded fluid and...
Coal is a low permeability solid medium with pores and fracture structures., pore penetration affects the coal seam permeability. In order to damage the porous structure of coal to achieve the purpose of increasing penetration, X-ray diffraction (XRD) and fourier transform infrared spectroscopy (FTIR) were used to study the changes of mineral composition, mineral crystal particle size,...
The characteristics of sandstone on the pore type, pore size distribution, pore connectivity, porosity and permeability with temperature were analyzed by scanning electron microscope, nuclear magnetic resonance and low pressure nitrogen adsorption. The pore size, pore size distribution, pore connectivity, porosity and permeability of sandstone in 25-800℃ range were analyzed. The SEM results...
The reserves of ＂three low＂ reservoirs in E1f2 layer of Jiangsu Oilfield are up to 63%, while the physical properties of the target block vary greatly, the microscopic pore structure is complex, and the occurrence state of oil and water is unknown. In view of the above problems, this paper starts from two aspects of reservoir understanding and percolation mechanism. Using the experimental...
The relative permeability behaviours of gas and water in coal are primary factors in the productivity of a coal seam gas reservoir, and it is dependent on many factors including fluid saturations and pressure, cleat geometry and network, and wettability (surface chemistry). In this study, we performed steady-state relative permeability measurements using X-ray CT scanner on packed beds of coal...
Gravity-driven water flow into an initially dry porous medium can lead to a non-monotonic behavior. Instead of a uniform flow front, water infiltrates in finger patterns, which has been observed experimentally [1, 3, 4]. Fingering effect cannot be described by the Richards equation or standard two-phase flow system unless some additional terms are incorporated. One of the most effective...
The present work proposes the use of General-Purpose Graphics Processing Units (GP-GPUs) to solve flow problems in large scale Discrete Fracture Networks (DFNs). Discrete fracture networks are randomly generated sets of planar polygons in the three dimensional space resembling the fractures in the subsoil. Recently a minimization approach was developed to tackle the issue of effective flow...
Gas transport in an unconventional reservoir is a complicated process that is highly subject to nonlinear multi-physics phenomena, such as gas molecule’s sorption and slippage effects especially in tiny pores. The quantity of the adsorbed gas release and gas permeability changes due to the complex gas transport phenomena can significantly affect the entire production in unconventional...
In view of the poor physical property of reservoir, the complicated microscopic pore structures and the difficulty of effective development in Fuyu Oilfield of Qingxin Oilfield, by comprehensively using constant pressure mercury intrusion, nuclear magnetic resonance (NMR) and physical simulation experiment system of oil-water displacement, the microscopic pore structure characteristics and...
A general framework for modelling hydromechanically coupled fractured porous media is implemented utilising the dual-continuum concept. Modelling fractured systems explicitly can be impractical at the field scale due to the size of the computational problem. Additionally, fracture properties are often not known unless directly accessed. The dual-continuum approach offers a practical method of...
Due to the differences in physical properties between clay mineral and sand matrix, clay content has always been an important part of reservoir evaluation. Clay content can be used to calculate effective porosity, saturation and permeability in conventional reservoirs and provide available information for brittleness evaluation and hydraulic fracturing design in tight oil reservoirs or shale...
One of the main objectives of oil reservoir geological modeling is to predict the spatial distribution of petrophysical properties from a few poorly distributed data. To achieve this goal, it is usually necessary to establish some dependence model so that it is possible to predict petrophysical properties of interest through its relationship with seismic attributes that are more densely...
For investigating the recovery mechanism of countercurrent imbibition in the process of hydraulic fracturing and shut in well in cyclic water injection, experiment system of countercurrent imbibition in tight oil reservoir and experiment method of flow resistance measurement caused by reverse displacement was established by high-pressure physical simulation system for large scale outcrops. Two...
With the development of tight oil reservoirs, various fracture-propagation models have been used to maximize the contact area between fracture network and reservoir matrix. However, the optimal results doesn’t necessarily obtain the maximum economic benefits. Also, many researchers developed reservoir simulators to optimize fracture parameters (e.g., half length, width, direction, et al.)....
Determination and Prediction of VOC Adsorption Performance Data of Activated Carbon Based Filter Media for Indoor Air Purification
*Roman Ligotski (1), Uta Sager (2), Christof Asbach (2), Frank Schmidt (1)
1 Nanoparticle Process Technology, Department of Mechanical and Process Engineering, University of...
From MRI visualization of internal liquid distribution in time during convective (given air flux) drying of uniform bead packings with pore size from micro- to nano-meter, we show that, at first sight, the standard regimes of drying may be observed in any case: first a constant drying rate regime (CRP) associated with a homogeneous desaturation, followed by a falling rate period (FRP)...
Many lacustrine organic-rich shales formations, deposited in saline basins or the salification stage of freshwater basins, are interbedded with carbonates, sulfates and chlorates minerals. Dissolution and precipitation of salt always happen during extraction of hydrocarbons from lacustrine shale reservoirs. The dissolution of sulfates and chlorates minerals causes reservoir deformation, while...
Tissue engineering consists in combining an absorbable scaffold with cells of interest and the proper culture medium in order to produce a tissue for medical purpose. In particular, bone tissue engineering steps in as a promising alternative to the current reference treatments auto and allografts [1].
The objective is two-fold: first, to understand how fluid flow in the porous scaffold of...
Fiber-based materials have an enormous industrial impact. This can be seen in the paper, apparel, and especially in filters, whose market is dominated by automotive applications. In all of these traditional materials cases, as well as emerging advanced materials, such as carbon fiber reinforced polymers (CFRP), the microstructure of the material profoundly impacts the macroscopic properties....
Leakage along wellbores is of concern for a variety of applications, including sub-surface fluid storage facilities, geothermal wells, and CO2 storage wells. We have investigated whether corroded casing is permeable to gas and can serve as a leakage pathway along the wellbore. Steel plates were corroded in corrosion reactor and sandwiched in a cylindrical...
Hydroxyapatite (HA) is the main inorganic component of human bone and therefore HA ceramics are widely used as artificial replacements for natural biomaterials, both for implant applications and bone tissue engineering scaffolds [1-3]. In order to ensure not only biocompatibility (bioactivity), but also osteoconductive and osteoinductive properties enabling bone cell ingrowth, as well as...
Hydrogels are the specific group of hydrophilic porous materials, being composed of variety of natural, synthetic polymers or their combinations. Their characteristic feature is the possibility to swell in aqueous solutions. Moreover, the relatively high porosity and water content, softness, strength and the ability of various substances to diffuse through the pores of their cross-linked...
The coupling between subsurface flow and geomechanical deformation is critical in the assessment of the environmental impacts of groundwater use, underground liquid waste disposal, geologic storage of carbon dioxide, and exploitation of shale gas reserves. In particular, seismicity induced by fluid injection and withdrawal has emerged as a central element of the scientific discussion around...
The use of petrophysical data and seismic attributes in the oil industry have allowed the characterization of the reservoirs due to their value as predictive tools, for the evaluation of reservoir information is needed the petrophysical parameters such as porosity, permeability, saturation, etc. And the seismic information can infer the physical properties of the rocks on the place (Li & Zhao,...
This study analysis micro production characteristic of tight oil reservoir cores, using NMR technology with core displacement test. Research show that: After water flooding for tight oil reservoir of Erdos basin: most of oil in micron pores and a majority of oil in sub micron had be driven out, and the lower permeability reservoir had, the higher recovery percent of reserves R sub micron pores...
The micro pore structure characteristics of the tight carbonate and sandstone reservoirs in Central Sichuan Basin were systematically studied, by using constant velocity mercury injection, high pressure mercury intrusion, specific surface area instrument and CT scanning, etc. the results indicate that under the same permeability, compared with the tight sandstone reservoirs, the tight...
To overcome the limitation of resolution and dimension of a single imaging method, a combination of X-ray computed micro-tomography (X-ray μ-CT) and focused-ion beam-scanning electron microscopy (FIB-SEM) tomography was employed to reconstruct the multi-scale 3D digital cores. First, macro-pore images were collected by X-ray μ-CT, and meso-pore images and micro-pore images were obtained by...
Several unconventional reservoirs have been stimulated using hydraulic fracking to enhance the production. Further, reservoir simulation technology is facing new challenges in providing key information used for long-term strategic decisions.
To understand and optimize shale reservoirs production, one must capture the role of hydraulically induced fractures, natural fractures and their...
Darcy flow in a two dimensional rectangular domain heated at the bottom and cooled at the top with perfectly insulated sidewalls is the topic of interest for this research. For Rayleigh numbers less than the critical value, $Ra_{cr}$, any disturbances will decay to a motionless solution and heat transfer will occur via conduction only. Above $Ra_{cr}$, natural convection develops in the...
Interfacial mass transfer between scCO2water in porous media is a key process for dissolution and mineral trapping of CO2 during geological storage of CO2. Recently, both core- and pore-scale drainage and imbibition experimental studies have shown non-equilibrium dissolution of scCO2 and an extended depletion of residual scCO2 (Chang et. Al. 2016, 2017). For better understanding and...
Fracture permeability that governs fluid flow within fractures is highly sensitive to fracture aperture that is affected by the fluid pressure on the fracture surface and far filed in situ stress. Previous research focused on fracture behavior in poroelastic medium with only stress and pore pressure boundary conditions on fracture surface. A more general solution should take into consideration...
Tight oil reservoirs have got extremely low permeability and porosity, with complex microscopic pore structures and fine pore throats, relatively large force of fluids acting on the rock surface of the reservoir, and uncertain regularities of oil & water distribution. Currently, tight oil reservoirs are mainly developed in the mode of quasi-natural energy exploitation using staged fracturing...
Carbon dioxide geological sequestration is an important technology for mitigating CO2 from being indefinitely emitted to the earth atmosphere. Injecting carbon dioxide, normally in a supercritical state, into carefully selected hydrocarbon or saline formations gives rise to several physical, chemical and thermo-hydro-mechanical processes occurring at the reservoir and the surrounding region....
Complex systems are often described with competing models. Such divergence of interpretation on the system may stem from model fidelity, mathematical simplicity, and more generally, our limited knowledge of the underlying processes. Meanwhile, available but limited observations of system state could further complicate one’s prediction choices. Over the years, data assimilation techniques, such...
Drying is a highly energy intensive unit operation in the process industry. Its high complexity due to the large number of interacting phenomena makes it very difficult to model. Thus far, modelling of drying was done using either continuum methods or pore network models, both of which have some limitations. In this work, the Lattice Boltzmann Method (LBM) is used to simulate the drying in...
Tight oil reservoirs are widely distributed around the world and playing an important role in the energy industry. Multistage hydraulic fracture technology has shown a great success in tapping these reservoirs because it improves fracture conductivity and brings higher oil yields. Nevertheless, enhanced oil production from stimulated tight reservoirs is challenging because of the complex...
In an enhanced geothermal system (EGS), fluid is injected into pre-existing fractures to be heated up and then pumped out for the electricity generation; injected fluid is cold as compared to surrounding bedrock. The rock-fluid temperature difference induces thermal stress along the fracture wall, and the large thermal stress could damage some of the self-propping asperities and result in a...
Accurate prediction of petroleum reservoir production in structurally weak geologic areas such as fractured reservoirs or low-permeability reservoirs requires both mechanical deformation and fluid flow modeling. Even production of reservoirs located in stable environments may also need to be predicted by fluid-solid coupled models in case of injection of water or carbon dioxide. The equations...
The particle-laden liquids and their interaction with a permeable medium are important in various industries. However, research into their interaction has been bifurcated into two independent directions: suspension flows in geometries with smooth surfaces and flows of pure Newtonian fluids over porous media. Derivation of experimentally validated models and theory, which predict their coupling...
Water-based polymers are often used to improve oil recovery beyond a waterflood by improving the mobility ratio and increasing sweep efficiency. However, polymer floods are not expected to affect residual (trapped) oil saturation. In this work, it is shown hat polymers, particularly those that are viscoelastic, can reduce residual oil saturation.
Bentheimer and Berea sandstone cores were...
Fluid flow in porous media has attracted enormous attention from academia and industry as it has numerous applications, such as hydrocarbon production, shale gas recovery, CO2 sequestration and ground water utilization, etc. The fluid flow is governed by different phenomena at different scales ranging up to 12 orders of magnitude in dimension (nm to 100 m), from nanoscale (pore proximity), to...
In this work we consider robust iterative methods for the effective simulations of poromechanics, which has plenty of societal relevant applications like geothermal energy, $CO_2$ sequestration or oil recovery, to name a few. We will focus on the quasi-static linear Biot model and non-linear extensions.
We start with the well-recognized fixed stress method [1, 2] and present some recent...
The present work deals with the highly efficient parallel implementation of an optimization-based solver for the flow in Discrete Fracture Networks (DFNs).
A DFN is a sets of mutually intersecting planar polygons in the three dimensional space, resembling a system of fractures in the subsoil. Fracture networks are stochastically generated to tackle uncertainty and lack of observations on...
At the Interpore 2017 meeting, we presented novel membraneless batteries based on two immiscible protic solvents (ethanol or methanol and saltwater). These batteries were also capable of producing hydrogen on demand, and hence allowed one to construct a system that both generated the power to compress hydrogen and simultaneously produce the hydrogen to be compressed.
Recently, several...
We present a theory of multicomponent mixtures which does not employ any splitting of component fluxes into convective and diffusive parts. Instead, momentum balance is formulated individually for each component in which both 1) viscous friction within a component, and 2) momentum exchange among different components, are taken into account. While the viscous friction is described using the...
Vapor-condensation and capillarity-driven, spontaneous imbibition allow one to fill nanoporous media in a controlled manner with molecular liquids. We present experimental studies on the dynamics of these filling processes for a variety of porous media (silicon, silica, and gold with pore diameters ranging from 2 to 100 nm). These experiments are aimed at an exploration of the rheology of...
Dissolution-driven convection in partially miscible systems has regained much interest in the context of CO$_2$ sequestration [1]. A buoyantly unstable density stratification can build upon dissolution of CO$_2$ into brine, thereby driving convection. Dissolution and convection are known to improve the safety of the sequestration process by reducing the risks of leaks of CO$_2$ to the...
A wide range of solid media gradually evolve into porous media containing a large number of pores, and sometimes voids and fractures, after a single or several coupled physical and chemical actions. This is a very common phenomenon in nature.
It Is extremely important in the field of science, engineering and biomedicine，a rise of the research direction and research subject.
The evolution...
Because of the current low oil price, the Oil and Gas industry needs to optimize their workflows. Digital rock physics (DRP) is the to determine physical rock properties by performing numerical simulations on 3D scans of rock samples. This innovative technique saves time and money in comparison to conventional lab experiments. Besides the increase in efficiency, DRP also allows insights into...
Accurate simulation of fault and fracture mechanics is a key component in a wide number of subsurface engineering applications. Faults and fractures are typically treated by modelers as discontinuity surfaces embedded in three dimensional (3D) continuous media. From a mathematical standpoint, they are described as internal boundaries whose behavior is governed by the displacement and stress...
Dissolution trapping is one of the mechanisms that contributes to stable storage of carbon dioxide (CO2) in deep geologic formations with brine. Basic to the process is the supercritical CO2 (scCO2) dissolving in the formation brine and the subsequent mixing of dissolved CO2 and brine in the deeper zones of the formation. In most conceptual models, it is assumed that the mixing is controlled...
Understanding the evolution of a hydrate-crusted gas capsule during its depressurization is critical to elucidating the fate of methane bubbles escaping from seafloor seeps, a process that controls the impact of seafloor methane leakage on ocean biogeochemistry. While the physics of rising bubbles in a water column has been studied extensively, the process is poorly understood when a hydrate...
Most oilfields in China are continental deposits, which show great heterogeneity and the deficiency of natural water energy. Nearly all these kinds of reservoirs have to be injected water to keep formation pressure and enhance recovery efficiency. The distribution of remaining oil in reservoir is extremely complicated after years of water injection. The accurate evaluation of waterflooded...
Flexible grids with local grid refinement can be used to model multistage fractured horizontal wells (MFHWs). To resolve multiple horizontal wells accurately, an ultrahigh mesh size is often required. Moreover the unstructured mesh and permeability contrast result in very expensive linear solution processes. It was observed however that most Newton update entries resulting from these systems...
Ubiquitous uncertainty about pore geometry inevitably undermines the veracity of pore- and multi-scale simulations of transport phenomena in porous media. It raises two fundamental issues: sensitivity of effective material properties to pore-scale parameters and statistical parameterization of Darcy-scale models that accounts for pore-scale uncertainty. Homogenization-based maps of pore-scale...
Macroscopic transport properties of porous media essentially rely on the geometry and topology of their pore space. The premise of predicting these transport properties is to construct an accurate 3D pore space. A new method for reconstructing 3D porous media based on a 2D slice using the multiple-point statistics (MPS) is proposed. To validate the accuracy of the technique, Berea sandstone is...
This study aims to understand with more amplitude and clarity the behavior of a porous medium where a pressure wave travels, translated into relative displacements inside the material, using mathematical tools derived from topology and symplectic geometry. The paper starts with a given partial differential equation based on the continuity and conservation theorems to describe the travelling...
In-situ recovery of oil shale is an internationally recognized clean and efficient technology for extraction kerogen from oil shale. The technology- in-situ inject superheated steam into oil shale to exploitate its kerogen, is a totally new technology proposed by Taiyuan University of Technology. In the process of in-situ pyrolysis and oil gas exploration of oil shale, pores and fractures of...
Geomechanical effects can have a first-order effect on production from naturally and hydraulically fractured reservoirs. Unstructured discrete fracture-matrix methods utilize conforming meshes with fractures represented by N-1 dimensional elements with local mesh refinement about them. Numerous coupled mechanics and flow models are employed on such mesh topologies. While these methods can...
It is widely excepted [1] that CCS (Carbon Capture and Storage) could play a major role in mitigating climate change associated with CO2 emissions. Variety of industrial scale of CCS projects provide strong empirical support for the view that CO2 storage can be implemented safely. Nevertheless, many uncertainties remain regarding the security of underground storage. The major technical concern...
Shale is a fine-grained sedimentary rock. Flow simulation in shale is challenging due to its multiscale porous structure (consisting of nano- to micropores and fractures) and multi-physics gas flow mechanism (including continuum flow, slip flow, transition flow, Knudsen diffusion and surface diffusion) in these pores. The available studies have provided preliminary understandings on the porous...
Sodium chloride crystallization is a key factor in many industrial and geological processes such as for deicing salts, in oil well drilling and CO2 sequestration, in the erosion of rocks, monuments and for the sodification of soils. Generally, salt crystallization in confined space, as encountered in porous media, can significantly change the porosity and permeability, and as such restrict...
Discrete Fracture Network (DFN) models are the geometrical basis for flow simulation of poro-fractured media in many industrial projects such as deep waste disposal, hydrogeology or petroleum resources. Because the spatial organization of fractures may control the hydrological and mechanical behavior of the fractured rock mass, the geometrical complexity of the network is a key point of the...
The surface chemistry discrepancy between microchips and real rocks/soils restricts the full application of microfluidics technology to subsurface energy and environmental research. Here, we creatively rebuild rock/soil surface chemistries in microchips by forming mineral coatings with an advanced coating technique - layer-by-layer (LbL) assembly technology.[1] The outcome of this work is a...
Various industrial processes involve two-phase flow in porous media. Examples are found in fuel cells, filtration, paper, food, concrete, ceramics, moisture absorbents, and membranes, to name a few. The common practice in modelling flow and transport in such porous media is to employ the concepts,
models, and algorithms developed in geosciences. However, many industrial porous media are...
Flow in porous media is occurring in a large number of industrial applications such as internal erosion in embankment dams, drying of iron ore pellets, composites manufacturing and paper-making, to mention a few. However, it is also occurring in a number of naturally formed materials, for instance snow. To know the flow through the snow is important when investigating the ageing of fresh snow....
In petroleum engineering, the production decline type curves for the analysis and interpretation of production data has been considered as a robust method to obtain the flow parameters, and original gas in place etc. However, most of the previous production decline analysis model focused on primary depletion with closed boundary, rather than secondary depletion with water influx/waterflood....
We present a detailed analysis of a “full physics” simulated drainage-imbibition capillary pressure hysteresis on a packed sphere test case, with particular focus on the fluid displacement mechanisms. The chosen LBM-based flow simulator includes a surface-element boundary scheme to ensure accurate surface treatment and robust handling of arbitrary geometries even in low grid resolution...
Micro-models are microfluidic devices used to study the transport of fluids in porous media domains. Porous media relevant to subsurface engineering and reservoir applications are 3D in nature. In order to observe and measure the transport and behavior of nano-particles through such media, it is necessary to preserve the 3D characteristics of the relevant geometry and flow while facilitating...
Accumulation of large particles on well faces decreases the injectivity. This issue is particularly accute in the case of produced water reinjection (PWRI) and polymer flooding. To maintain operational rates, the injection pressure is increased, which causes fracturing or reopening of existing fractures. Then, the injectivity may be recovered or even increased, but only temporarily, as filter...
Modeling nanoparticle (NP) transport in porous media is an important research topic in many subsurface engineering applications, such as enhanced oil recovery (EOR), fracture electromagnetic imaging and environmental remediation. An efficient field-scale simulation framework is critical for predicting NP performance and designing subsurface applications. In this work, an efficient...
Surface charge at solid-electrolyte interface is generally affected by the local physical and chemical properties in the solution such as ionic strength, pH and so on. In a system with concentration or pH variation, rather than the prevailing assumption of homogeneous surface change, it leads to a spontaneous inhomogeneous distribution of surface charge, which has been observed in geotechnical...
