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Because underground hydrogen storage offers the potential for large-scale, long-term storage of hydrogen, understanding the adsorption and diffusion behaviors of hydrogen and cushion gas in the reservoir is critical to understanding the underlying mechanisms that control hydrogen storage and transport. Using molecular simulation methods, we investigated the adsorption and diffusion behaviors...
CO2-EOR (enhanced oil recovery) represents one of the most cost-effective methods for achieving carbon neutrality. However, CO2 flooding encounters serious preferential flow in porous mediums, which significantly reduce the economic benefits of CO2-EOR and exacerbate the risk of CO2 leakage. This study synthesized a tertiary amine-based, CO2-responsive microgel. The microgel possesses a...
Porous media contains a huge amount of nanopores, and the behavior of confined fluid phases in nanopores will be affected by significant interfacial effects between the fluids and the walls. A large number of publications have recently investigated the influence of interfacial effects on the phase behavior of confined fluids in nanopores. Many influences such as adsorption, critical shift,...
Channelized reservoirs, formed by ancient river sands, play a crucial role in oil and gas reservoirs. Their subsurface nature, however, poses significant challenges in direct visualization and characterization. This paper presents a novel approach to model these reservoirs by applying Q-learning, a machine learning technique. We redefine the reservoir modeling problem within a Q-learning...
The South China Sea, endowed with abundant natural gas hydrate resources, presents exceptional conditions for gas hydrate formation and exploration prospects. Gas hydrate-bearing sediments are characterized by methane saturation in pore waters, fostering rich and distinctive microbial ecosystems. These microorganisms play crucial roles in methane production, consumption, and global carbon...
Hydraulic pulsing is a widely used technology for cleaning, hydro-shredding, and soil improvement. In recent years, low-frequency hydraulic pulses have been used in oil and gas development, such as wellbore blockage removal and EOR. The effectiveness of this process depends on the attenuation pattern of the hydraulic pulse wave in the reservoir. In this paper, a numerical model of...
The phenomenon of the Stokes–Darcy flow in coupled systems comprising a clear channel and a complex 3D porous medium is investigated through numerical and theoretical approaches. A quartet structure generation set (QSGS) method is used to generate random complex 3D porous structures imitating real structures in nature. Pore-scale flow simulations are performed using the Lattice Boltzmann...
The study of trapping and releasing nonwetting droplets in porous materials has been extensively explored. However, dynamically characterizing residual nonwetting droplets under vibrations within porous media remains a challenging endeavor. Current theoretical models addressing seismic responses in two-phase flow primarily focus on single-channel geometries with fixed pressure differentials...
In the realm of geosciences, the phenomenon of fines migration and subsequent clogging in rock formations presents a complex challenge. This process can occur even when fines are smaller than a specific threshold size, known as the critical throat diameter. The dynamics of pore clogging involve interactions on multiple scales - ranging from the transport at the pore level to the mechanical and...
Wettability is an important factor controlling the pore-filling mechanism and displacement efficiency in the subsurface pore space. The trapped phase can be mobilized by wetting alteration, which is one of the main mechanisms of enhanced oil recovery technologies, such as surfactant flooding and low-salinity water flooding. Despite recent advances in the simulation of wetting alteration at the...
The influence of flow regime and soil saturation on solute transport processes is significant, yet the associated effects have not been adequately addressed. To address this gap, we conducted three sets of solute transport experiments in a sandy soil, complemented by numerical modeling, under both steady-state and dynamic drainage conditions. The results from steady-state experiments revealed...
The inversion and uncertainty quantification of parameters associated with governing PDEs are important in many scientific and engineering problems. For example, petroleum reservoirs are typically heterogeneous and uncertain due to the sparsity of hard data, and the uncertainty quantification of physical parameters associated with the governing PDEs of flows in porous media, given production...
Many studies have been dedicated to examining flow regimes using two key parameters: viscous ratios and capillary numbers Ca. However, only a few studies have elucidated mechanisms that govern different flow regimes and how the work of displacement and surface aeras alter within porous media, as well as their influence on flow behavior is still unknown. In this study, we experimentally...
Pore-scale modeling developed over the past decades has become a powerful method to evaluate the effective transport properties of porous electrodes. Experimental verification for such a method is crucial to confirm the method's validity. In this study, experimental data of gas diffusion layer (GDL) are compared with results of pore-scale modeling. GDL microstructures are scanned and...
Soil Organic Carbon (SOC) is a fundamental component of terrestrial ecosystems, connected to climate regulation, nutrient cycling, and soil health. The influence of soil salinity - referring to the concentration of soluble salts in the soil solution - on SOC content is acknowledged (1,2), but there is limited understanding regarding the precise direction and extent of SOC’s response to varying...
Deep shale gas will become an important part of supporting the growth of China 's natural gas production. Compared with the middle shale and shallow shale, the properties and porous flow laws of deep shale gas are more complex. The nano-confinement effects such as adsorption and slippage cannot be ignored in the study of porous flow mechanism of deep shale gas. When the porous flow law of deep...
The structure of the sample defines its physical properties. The homogenization based on different fields (e.g., pressure and velocity for permeability property) produces general property of the sample. For this property to be useful for continuum-scale modelling it has to be representative for the volume it will be substituted for in the next level model. This explains the importance of...
Hydraulic fracturing is an important stimulation technique for extracting resources from low-permeable formations. Apart from hydraulic fracturing (where pore pressure exceeds the minimum principal stress), hydraulic shearing (where pore pressure does not exceed the minimum principal stress) is an essential mechanism in forming the stimulated reservoir volume and controlling the ultimate...
Low salinity water flooding (LSWF) is novel technique which can be used to improve oil recovery for sandstone reservoirs. Although considerable experimental research has been conducted to identify the underlying pathways, there are a lot of debatable issues with the mechanics. On the basis of molecular simulation (MS) method, the models of rock, oil and brine in different salinity and ions...
Various studies have confirmed that water salinity and composition significantly impact the efficiency of the waterflooding process. Field-scale operation of low-salinity water injection has been proven to be a cost-effective enhanced oil recovery (EOR) method as well as compatible with environmental regulations. The success of this technique relies on the contact of low-salinity water with...
Crude oil is a complex mixture of organic compounds which are conventionally categorized as saturates, aromatics, asphaltene and resins based on their polarity and solubility. Aromatics, in particular, comprise a large portion of many light, medium and heavy oils therefore it is important to understand their interfacial properties with water and surfactants in the context of enhanced oil...
Polymer fluids, a blend of polymers in water, offer a cost-effective and environmentally friendly solution for supporting deep underground excavations. However, being non-Newtonian fluids, their full potential in construction projects is hindered by a limited understanding of their behaviors. In this study, we will employ a combined approach of DEM-based and micro-CT imaging techniques to...
In oil-gas-water three-phase systems, CO2 can be distributed either as a non-wetting phase, or as an intermediate-wetting phase. The morphology and distribu-tion of CO2 clusters under different wetting sequences are different, which has a complex influence on CO2 dissolution process. Based on phase distribution ob-tained from three-phase flow experiment, we constructed the physical models of...
We report an anomalous capillary phenomenon that reverses typical capillary trapping via nanoparticle suspension and leads to a counterintuitive release of nonaqueous fluid from dead-end structures under weakly hydrophilic conditions. Fluid interfacial energy drives the trapped liquid out by hierarchical surfaces: the nanometric roughness formed by nanoparticle adsorption transfers the...
Microemulsions exist widely in nature, daily life and industrial manufacturing processes, including petroleum production, food processing, drug delivery, new material fabrication, sewage treatment, etc. The mechanical properties of microemulsion droplets and a correlation to their molecular structures are of vital importance to those applications. Despite studies on their physicochemical...
Oil mobility evaluation is the primary topic in shale oil development. The different occurrence states of shale oil, which closely relate to the pore structure and fluid properties tremendously affect the oil mobility in shale. As proved in previous studies, the higher the content of oil in free states, the better the oil mobility will be. In this study, the oil occurrence states and its...
We provide the theoretical foundation of directly adopting the Klinkenberg plot, the apparent permeabilities versus the reciprocal of the mean pressures, in Pulse Decay Method to eliminate the slippage effect, which is characterized by the Knudsen number and strengthens with the decrease of permeability, by asymptotic perturbation of Navier-Stokes equation in capillaric model in this work....
The classical advection-dispersion equation has been a cornerstone in aquifer solute migration studies for decades. However, prevailing misunderstandings regarding advection-dispersion dynamics, their interplay with heterogeneity scales, the nature of ensemble averages, and their observational implications have sparked intense debate concerning the equation’s conceptual validity. Addressing...
Studying the interactions among microbes within rock pores and their impact on mineral phases is essential for comprehending subsurface ecosystems and biogeochemical processes, particularly in the realm of subsurface energy operations. In this paper, we introduce an approach that merges customized sample preparation methods with traditional Scanning Electron Microscopy (SEM) featuring...
The lunar surface is covered with a layer of lunar regolith. Observational evidence[1-3] suggests that it may contain volatile substances such as water, methane, and helium-3 that could be utilized. Studying the diffusion behavior of volatiles in lunar regolith is of great significance for the exploration and exploitation of these extraterrestrial resources.
Volatile in lunar regolith layer...
The complex phase behavior of hydrocarbon mixtures is encountered in miscible flooding in the oil-saturated reservoir and liquid dropout in gas-condensate reservoir. In pore-network models, phase equilibrium calculations (Michelsen, 1982) have been coupled with convective-diffusion equations to evaluate the influence of hydrocarbon phase behaviors to flow and transport at given hydrocarbon...
In this paper, we propose a pore-scale lattice Boltzmann model to treat heterogeneous surface reactions coupled with mineral dissolution. The primary innovation lies in the transformation of surface reactions, originally treated as boundary conditions, into volume source terms through dimensionality augmentation within the framework of sharp liquid-solid interfaces. This significantly...
CO2 displacement is considered as a potential method to enhance shale oil recovery. CO2 can reduce the viscosity and surface tension of crude oil, making it possible to recover crude oil in the nanopores. At the same time, the CO2 can also be partially stored underground, reducing the carbon footprint of the hydrocarbon extraction process. Therefore, understanding the CO2 displacement in...
Abstract. Geologic sequestration of carbon dioxide (CO2) is one of the most significant technologies to combat climate change at present. Nevertheless, the CO2 injected into shale reservoirs can expand to affect the permeability and strength of the reservoirs, affecting the efficiency of injection and the safety of storage. In this work, the strain behavior of He (1300 psi) andCO2 (850 psi) on...
The undesired CO2 hydrates formation in wellbores or pipelines often poses a significant risk to production safety. CO2 hydrates can develop during numerous processes, such as CO2 injection for geological or saltwater storage, production wells in CO2 flooding for enhanced oil recovery, and CO2 pipeline transportation. These hydrates form when gas-water two-phase conditions are met within the...
Tight sandstones are characterized by low porosity and permeability, high clay content. Measuring the rock physics properties under low water saturation conditions using the displacement method poses significant challenges. Digital rock physics (DRP) has been emerged as a valueble method for studying of rock physics of unconventional reservoir. It should be noted that the resolution of X-ray...
Abstract: Spontaneous imbibition is a process in which porous media spontaneously inhales wetting liquid driven by capillary force, which is an effective means to enhance oil recovery in tight reservoirs. At present, the observation methods of spontaneous imbibition mainly include nuclear magnetic resonance method and computer tomography method. In this paper, the method of ultrasonic testing...
In the process of forming porous media by deposition of particles, due to factors such as deposition rate, gravity sorting effect and fragmentation of coarse particles, different structures of interlayers are usually formed, and the form of distribution of interlayers has an important effect on the stress distribution, structural strength and deformation properties of the porous media....
Direct liquid fuel cells have become an ideal power source for rapidly emerging miniaturized and portable electronic products due to their advantages of cleanliness, environmental friendly, high efficiency, safety, long endurance, and fast "charging". However, at present, the cathode catalysts for oxygen reduction reaction (ORR) of such fuel cell are still mainly platinum or platinum-group...
The type of free gas transport in shale gas formations includes viscous flow, slip flow, and Knudsen diffusion. These three types of transport are categorized based on Knudsen number (Kn), which is defined as the ratio between the mean free path (MFP) of gas and the pore width. The MFP of gas in nanopores is usually estimated based on the ideal gas model. However, the gas in the nanopores is...
The pore water retained in the unsaturated soil includes film water stagnant on the solid surface and capillary water in corners or pores, which can be morphologically quantified by film thickness and radius of meniscus curvature, respectively. The current procedure and theory of soil water retention (SWR) measurement assume that capillary water and film water are connected in the medium...
Passive and directional droplet transport has gained significant interest due to their potential applications, e.g., self-cleaning surfaces and atmospheric water harvesting. One novel mechanism, known as bendotaxis, involves droplets spontaneously deforming an elastic channel via capillary pressure, thereby inducing droplet motion. However, current studies have primarily focused on parallel...
In this study, the effect of catalyst particle size on the performance of proton exchange membrane water electrolyzer (PEMWE) was studied by using the Lattice Boltzmann Method (LBM). The results show that compared with the catalyst particle distribution, the catalyst particle size is the main factor affecting the performance of the catalytic layer of the anode. Homogenized catalyst particles...
Coupled fluid-porous systems appear routinely in environmental, biological, and industrial applications. The flow interaction between the free fluid and the porous medium is strongly interface driven and can be described by the sharp interface or the transition region concept. Classical interface conditions based on the Beavers--Joseph approach are valid only for unidirectional flows parallel...
It is not uncommon for porous media to span multiple scales of heterogeneity. Geological formations are examples of such complex systems that may act as natural aquifers, hydrocarbon reservoirs or greenhouse gas sequestration units. Application of conventional single scale modelling approaches is not sufficient for representative prediction of flow in such heterogenous permeable media....
Recently developed image-based computational fluid dynamics (ICFD) techniques have revolutionized the study of pore-scale porous media flows (PSPMFs) by allowing for simulations within realistic porous structures extracted directly from images. Pore-scale fluid dynamics delve into the fundamental physics governing flow, transport, reaction, adsorption, and deformation within heterogeneous...
Hydrogen, as a promising clean energy source, holds significant potential for energy transition and the efficient utilization of clean energy. However, large-scale hydrogen storage poses a limitation to its large-scale utilization and further development. Saline aquifers, characterized by favorable pore space and temperature-pressure conditions, are considered promising candidates for...
The precipitation of secondary phases in porous media carries profound implications for the functionality and efficiency of diverse natural and engineered systems. This encompasses applications ranging from subsurface CO2 storage sites, geothermal systems, deep geological disposal repositories, tunnels, oil and gas reservoirs, to the treatment of contaminated groundwater. These precipitation...
In carbon sequestration projects, ensuring the safe management of reservoir pressure is essential for long-term security. The injection of CO2 can lead to pressure build-up, risking safety issues like caprock damage, induced seismicity, and potential leaks. While brine extraction offers a practical solution to mitigate those safety issues, it is crucial to optimize the location of the brine...
The crucial role of the interaction between Pickering emulsions and confined nanochannels in their industrial applications is well acknowledged. However, there is a limited understanding of how the modulation of deformation stability and rupture limits of Pickering emulsions occurs when they come into contact with solid walls, particularly in relation to the influence of solid particle shells....
Microbial Induced Calcite Precipitation (MICP) technique is a "green" bio-grouting method developed in recent years, which has been applied in many engineering fields. The MICP technique has attracted extensive attention due to its high reinforcement strength and environment-friendly properties. However, MICP reinforcement often faces the problem of non-uniformity precipitation, which happens...
Yttrium oxide is a promising and poorly studied material for the field of catalysis. It can be used as a support in catalytic processes such as carbon dioxide reforming of methane and $CO_2$ methanation. Predicting changes in the texture of $Y_2O_3$ during temperature treatment is an important material science and a computational task.
In this study, we applied a phase-field approach to...
To ensure the safety and reliability of batteries it is critical to accurately estimate the internal state of the battery which is crucial in Battery Management Systems (BMSs). It is crucial to have methods which, aside from yielding accurate predictions, can be applied for real time estimations. However, the advanced BMSs generating accurate results are computationally intensive and...
The relative permeability curve is one of the key features to evaluate the flow property of a porous medium, which is important in many subsurface engineering problems such as underground energy storage and recovery. Recently, rapid developments in the technology of artificial intelligence (AI) have offered new views to revisit the acquisition of relative permeabilities. Here, we present our...
As the most effective reservoir stimulation technique, hydraulic fracturing has been applied since the 1950s. At the same time, hydraulic fracturing can induce seismicity or result in the loss of containment of subsurface fluids due to the high injection pressure applied during its operation, leading some projects to eventual shut-down. To mitigate such adverse impacts, an alternative approach...
RepoTREND [1], [2] is a novel simulator that has been designed to emulate the processes that occur within a radioactive waste repository in a variety of geological formations. It provides robust functionality to simulate the release and migration of contaminants from the near-field through the geosphere to the biosphere, while estimating their radiological impact on human health and the...
Carbonate rocks exhibit a complex surface charge, making it challenging to generalize the use of a single surfactant type. Hence, the utilization of binary surfactant mixtures is proposed as a more efficient alternative. This work focuses on static adsorption, wettability alteration, and spontaneous imbibition tests to gain comprehensive insights into the underlying fluid-rock interactions in...
CO2 flooding after water flooding can effectively improve the recovery efficiency of low-permeability reservoirs. At present, the seepage law of CO2 flooding after water flooding is generally determined through indoor core experiments and macroscopic numerical simulation methods, and simulations of the seepage process at the microscopic pore scale are lacking. Among the existing microscopic...
Storing hydrogen in depleted gas reservoirs is a viable method for balancing seasonal energy demand fluctuations. However, these reservoirs harbor a diverse population of microorganisms. H2 are considered one of the most important electron donors for subsurface microbial respiration. Under high salinity, high temperature, and high pressure conditions, microbial reactions such as methane...
Hydraulic fracturing has gradually increased as an important means to enhance production in deep low permeability reservoirs. Whether proppant can maintain long-term high conductivity in fractures has become a hotspot. Quartz sand has been widely used due to its affordability and easy preparation. However, the strength of quartz sand is low. Under high closure stress, quartz sand is crushed,...
Shale oil is an abundant unconventional resource in the world. However, due to the highly heterogeneous of shale reservoirs, the shale oil is difficult to flow in the porous media, resulting in the uncertainty efficiency of industrial exploration for shale oil. Threshold pressure gradient is the key property to characterize the mobility of shale oil. Usually, shale rock has abundance of pores...
Multiphase flow in granular materials is intricate and subject to pattern formation resulting from the interplay between hydrodynamic and mechanical forces. While considerable effort has been devoted to studying systems with cohesionless grains, our understanding of the two-phase flow behavior through the cohesive counterpart held together by intergranular bonds is limited. Herein, we study...
Shale is a highly heterogeneous porous material rich in organic matter. Injecting fluid into a porous material can expand the pore space, distorting the solid skeleton. The detailed flow and mechanics of this solid deformation has not yet been systematically investigated. This work reports on modelling steady liquid flow in shale system, considering the slip effect and fluid-structure wall...
Geochemical reactions are crucial for in-situ CO2 mineralization underground associated with CO2-enhanced oil recovery (CO2-EOR) in a hydrocarbon reservoir. However, the presence of formation water and adsorbed oil on rocks generates physical barriers to CO2’s access to mineral surfaces, which may yield impedance to CO2 mineral trapping that has yet to be accounted for. In this study, we mimic...
The understanding of the seismic signature of the partially saturated formation is critical to seismic monitoring in the hydrogen geo-storage, CO2 geo-sequestration and geophysical survey and exploration of oil and gas reservoir. The main objective of this study is to model the wave propagation in partially saturated rocks containing two immiscible fluids (i.e., gas-water), with a comparative...
Prediction of aerosol deposition in the respiratory tract has become a major focus for inhaled drug delivery and air pollution prevention. Computational fluid-particle dynamics (CFPD) provides the most accurate local prediction results, but the computational cost is unbearable for the CFPD simulation of the whole respiratory tract. This challenge arises due to the multiscale nature of the...
Manual interpretation of geophysical logging data can be a tedious and time consuming task in the case of the non-linear behavior of well-logging signals. In this study, we introduced three novel algorithms including GrowNet, Deep-Insight and blender in the classification of rock facies. To compare the performance of these models, we used algorithms such as XGBoost, Random Forest and Support...
There are technical difficulties in accurately controlling and evaluating the micro-distribution mode and saturation of hydrate in physical simulation experiments. Limitations exist in the experimental technologies for investigating acoustic properties of hydrate-bearing sediments and establishing interpretation models of reservoir parameters. The acoustic properties of hydrate-bearing...
The intermittency in energy supply and demand from renewable resources, which is often caused by seasonal variations, necessitates the development of long-term energy storage solutions. One promising approach is Underground Hydrogen Storage (UHS), a scheme in which hydrogen is strategically stored in subsurface formations to maintain market equilibrium. Depleted oil and gas reservoirs and...
Permeability plays a pivotal role in governing the fluid flow within hydrate-bearing sediment (HBS) and significantly influences the efficiency of natural gas production from hydrate reservoirs. However, the measurement of HBS permeability is challenging due to the complexities of maintaining phase equilibrium conditions during testing. This study focused on the sandy hydrate-bearing sediments...
Estimation the capacities for CO2 storage plays a pivotal role in carbon capture and storage (CCS) projects. The material balance equation (MBE) approach, commonly applied in this domain, provides direct estimations of CO2 storage potential. Traditional MBE techniques, however, often compute the original fluid in-place volume via volumetric assessments without subsequent validation, posing...
Many underground rocks have been found to possess complex multiscale porous structures with bimodal/multimodal pore size distributions, such as carbonate rocks, tight sandstones, and shales (Bultreys et al., 2016; Shan Wang et al., 2022; Nijat Hakimov et al., 2022). Flow and transport in these rocks play an important role in many subsurface applications. In addition to in-situ core...
Continental shales are characterized by their highly developed laminations and a high clay content, which pose significant challenges in terms of sample preparation and fluid saturation process for traditional rock physics experiments. Digital rock physics (DRP) has been emerged as an alternative method for unconventional reservoir. The establishment of a high-precision three-dimensional...
The shale in the Kongdian Formation, Bohai Bay Basin is one of the leading shale oil targets in China and attracted attention from both industry and academics since the 2010s. Shale oil is known to distribute in the $\mu$m to nm pores in the shale formations. The oil compositions and pore spaces of shale formations strongly influence the shale oil production behavior for an efficient...
Understanding how hydrodynamics of multiphase flow couple porous media deformation is essential to ensure successful engineering practices such as geological carbon sequestration. However, existing hydro-mechanical coupled models face significant challenges in reliably and efficiently capturing fluid-grain displacement patterns. In response, we present a novel two-way coupled hydro-mechanical...
CO2 injection into shale is believed beneficial for both enhanced gas recovery and CO2 storage. The confined space and strong solid-molecule interactions in nanoporous media lead to different occurrence states of CH4 and CO2, causing the flow of CH4 - CO2 mixture in shale to deviate from predictions of continuum models. In this study, we employed a modified pseudo-potential based lattice...
Dynamic imaging of multiphase flow in porous media using X-ray microcomputed tomography (micro-CT) has been a technique exclusive to synchrotron-based systems. With the emergence of deep learning, however, the lower X-ray flux from a standard micro-CT system, and thus lower signal and higher noise under dynamic imaging conditions can be compensated for by use of convolutional neural networks...
Cementitious materials, known for their brittle nature, are often vulnerable to thermal degradation in deep underground and hydrothermal environments. Basalt fiber (BF), an inorganic silicate additive used in cement, has garnered significant attention due to its outstanding mechanical and thermal resistance properties. However, key experimental data are scarce on the role of BF in cement...
In this research, the effect of the pore size of the electrospun membrane in the preparation of a three-layer thin film nanofiber composite membrane (TFNC) was investigated. Due to its special properties, such as high porosity and the ability to produce pore sizes ranging from tens of nanometers to several micrometers, along with different mechanical properties, it finds wide applications in...
Asphalt pavement is widely used in road construction due to its smoothness, wear resistance, and ease of maintenance, making it the most commonly chosen material. However, asphalt concrete exposed to the natural environment is susceptible to various external factors, resulting in different types and degrees of damage. This greatly shortens its service life and reduces the durability of asphalt...
Unsaturated flow in fractured media is an important process with relevance to a large number of industrial and environmental application. In this work, we report recent experimental and theoretical investigations on unsaturated flow in single fractures, fracture intersections, and fracture networks. Wo focus on how small-scale flow physics influences the spatial and temporal characteristics of...
Meng Du1,2,3, Shuyi Lu4, Zhengming Yang*1,2,3, Weifeng Lyu1,2,3, Xinliang Chen2,3, Xiang Qi 3, Pengwei Fang 1,3, Zhuoying Dou 1,3
(1. University of Chinese Academy of Sciences, Beijing 100049, China;2. Institute of Porous Flow & Fluid Mechanics, Chinese Academy of Sciences, Langfang 065007, China; 3. Research Institute of Petroleum Exploration & Development, PetroChina, Beijing 100083, China;...
The global progress with the energy transition from fossil fuels to renewable energy has boosted the demand for metals. Copper, amongst all metal resources, is regarded as an essential raw material in producing the conduit to reduce the energy needed during electricity production. Most of the low-grade copper is recovered from heap leaching, which is a well-established hydrometallurgical...
Li-ion battery is a complex physicochemical system that generally takes observable current and terminal voltage as input and output, while leaving some unobservable quantities, e.g., Li-ion concentration, for serving as internal variables (states) of the system. On-line estimation for the unobservable states plays a key role in battery management system since they reflect battery safety and...
The mechanical parameters of reservoir rocks play a crucial role in the evaluation of unconventional reservoirs. However, due to time and cost constraints, conducting rock mechanics experiments on all formations is not feasible. Furthermore, conventional testing methods may not accurately characterize and test rocks with complex micro-structures, such as tight sandstones and shales, where...
The evaluation of fracture construction processes hinges on the critical factors of conductivity and the validity period of artificial fractures. It is imperative not to overlook the conductivity damage resulting from the crushing of proppant particles. Being a specialized geotechnical granular material, proppant particles undergo fragmentation when the applied compressive load surpasses their...
Water flooding is one of the important ways of oilfield development in China. However, due to the poor-compatibility between injected water and reservoir rocks and fluids, free particles such as inorganic scale and rock clay often block the pores and throats under the carry-over effect of water seepage, which leads to engineering problems such as water injection pressure increasing,...
Tight oil reservoirs are typically developed through hydraulic fracturing to create a network of fractures, with counter-current imbibition between fractures and matrix playing a crucial role. However, during the counter-current imbibition process, as water displaces oil, it increases water saturation and leads to water blocking phenomena, resulting in reduced oil relative permeability and...
The attributes of shale pore structure govern the accumulation, presence, and dissipation of gas. Deep marine shale undergo intricate geological evolution, with pore development at the nanoscale. Consequently, quantifying the impact of deep shale pore structure on gas is challenging. In this paper, the microscopic storage space structure of deep shale is quantified, and the correlation between...
Polymer electrolyte membrane fuel cells (PEMFCs) have emerged as ideal energy-conversion devices for hydrogen energy applications. The performance of PEMFCs is significantly affected by the accumulation and transport of water inside porous components and flow channels. Here, we focus on investigating the role of surface roughness on the fluid transport and droplet impact behaviours in the...
The characterization of electrical transport properties through porous media is commonly used for reservoir formation evaluation, groundwater management, mineral exploration, and carbon capture and storage (CCUS) monitoring. We discuss image-based characterization and prediction of a range of transport properties including, but not limited to, flow/momentum transport, mass transport as well as...
Accurately predicting future well response is crucial for making investment decisions in developing subsurface reservoir resources. Future well responses have been forecasted using history-matching methods, but traditional history-matching methods often incur high computational costs in calibration steps and have difficulties in maintaining geological constraints. Recently, data-driven...
The total storage of gas in a mesoporous material MCM-41 with adsorption/capillary condensation was measured using a new oscillation-based method. With an improved setup and procedure, the accuracy of the measured isotherm was significantly improved. Experiments were conducted using both condensable (propane and carbon dioxide) and non-condensable (argon and methane) gases. The results show...
Underground H2 storage is arguably considered one of the promising techniques to achieve net-zero emissions goals. The storage of H2 in geological formations is influenced by a complex function of the physicochemical, petrophysical, and geo-mechanical characteristics of the H2/brine/rock system. This results in the existence of different trapping mechanisms (e.g., residual and dissolution...
In this study, a body force driven two-phase fluid flow in porous media is numerically simulated by weakly compressible smoothed particle hydrodynamics, a Lagrangian mesh free particle method. The dispersed phase consists of viscoelastic emulsive droplets and is assumed to obey Oldroyd-B rheological model. The background phase is a Newtonian fluid. The interfacial tension between two phases...
Nanoparticles anchored on the perovskite surface have gained considerable attention for their wide-ranging applications in heterogeneous catalysis and energy conversion due to their robust and integrated structural configuration. Herein, we employ controlled Co doping to effectively enhance the nanoparticle exsolution process in layered perovskite ferrites materials. CoFe alloy nanoparticles...
High flow rates within reactive porous media occur both in industrial applications and in natural media, e.g. in permeable soil substrates subjected to extreme weather events [1,2]. The reactive surfaces of the soil grains interact with the transported species, determining the overall porous media reactivity and capacity of retaining nutrient and contaminants. We show via pore-scale...
The Chang 6 reservoir represented by Wangyao Area in Ansai Oilfield is the earliest developed reservoir in Changqing Oilfield. After nearly 40 years of exploration and development, the comprehensive water cut has reached 72.8%, and the degree of geological reserves recovery is only about 17.8%. The reservoir has entered the middle and late stage of development, and the reserve-production ratio...
Super-resolution imaging, a transformative technique spanning various scientific disciplines, holds the potential to revolutionize our understanding of complex porous structures within the realm of porous media and modeling. Traditional imaging approaches often struggle to capture the intricate details of porous media's intricate structures. To overcome this limitation, our research employs...
Investigating the distribution patterns of hydrates in the pore spaces of sedimentary rocks and their resistivity characteristics is crucial for understanding and predicting the storage and extraction of natural gas hydrates. However, CT and resistivity joint measurements indicate that while the distribution of Tetrahydrofuran (THF) hydrates in sandstone sediments is similar to that in...
Thermal conductivity is a key parameter dominating the heat transfer process in a number of engineering applications such as geothermal exploitation, borehole thermal energy storage and carbon dioxide geo-sequestration. Since soil consists of multiple phases including solid particles, gas and/or water, not only the physical properties of these phases but also the routes that they form affect...
The micro and nano structures of porous material have strong influence on their transfer properties such as porosity, permeability, tortuosity and adsorption isotherm curves. In the construction and building material field, these properties are strongly related to hydro and thermal comfort, due to the fact that heat and mass transfer mechanisms are determined by the micro porous structure. In...
The underground reservoir is a typical porous system, and the oil is stored as fluid in the pores of the reservoir. The efficient extraction of oil, which is primarily dependent on the reservoir development scheme, is a significant challenge. However, traditional reservoir development optimization methods mainly rely on manual experience or limited numerical simulation-based comparisons of...
During the condensate gas production process, condensate oil will precipitate, the phase state will change, and the seepage mechanism is complex. There are currently few analytical models for multiphase flow. Therefore, a semi-analytical method for three-phase flow production in condensate gas reservoirs is studied. Considering the vaporized oil ratio, solution gas-oil ratio, and solution...
In response to the low porosity and permeability of shale oil reservoirs in Block A, as well as the difficulty in producing shale oil, nuclear magnetic resonance experimental technology and high-temperature and high-pressure CO2 huff and puff experimental technology were used to study the effects of shale oil huff and puff pressure, extraction rate, maturity, and shale oil composition on CO2...
Electrodialysis (ED) technology relies on the selective permeability of ion exchange membranes, which allows for the separation of ions in a solution under the influence of an electric field [1,2]. ED has been frequently used for recovery of acids and bases [3,4]. Due to the growing demand for electric vehicles and the crucial need for recycling the lithium-ion batteries (LIBs), this study...
Natural gas hydrate is a potential new type of energy, mainly found in sediments in marine or terrestrial permafrost regions. The content, distribution, and growth or decomposition of natural gas hydrates in sediment pores or fractures, greatly affect the physical properties of the medium. This study mainly introduces the experimental techniques and methods for micro and nano scale imaging of...
Deep-water limestone reservoirs contain a large amount of oil and gas resources. Acid fracturing is an important technical means for the development of carbonate reservoirs, and the compatibility between the acid fracturing method and formation directly determines the development effect of reservoir. A large number of argillaceous and silty globigerina limestones deposited in deep-water...
Study on the Fluid Mobility Within Reservoir Microscopic Pore Throats Holds Significance for the Precise Evaluation of Reservoirs and the Efficient Development of Oil Fields. Nuclear magnetic resonance can rapidly and accurately determine common movable fluid parameters such as movable fluid saturation, movable fluid porosity, and bound fluid saturation. This enables effective fluid assessment...
Numerical simulations become necessary when experimental approaches cannot cover the required physical and time scale of interest. One such area is a simulation of long-term host rock behaviors for nuclear waste disposal and simulation tools involved in the assessment must go through rigorous validation tests. The DECOVALEX project (Development of COupled models and their VAlidation against...
Porous media have a wide range of applications in various engineering fields. Accurate modeling microstructure of porous media is the basis for subsequent numerical analyses and structure–property relationship researches. Computational reconstruction methods play an important role in these studies, can address limitations of some imaging techniques that are difficult to directly model...
Recent breakthroughs in deep neural networks have brought about transformative insights into the realms of physics, engineering, and scientific computing. Addressing the integration of neural networks with physical simulation remains a paramount research focus, where the physics-informed neural network (PINN) stands out as a widely adopted framework due to its versatility in...
In unsaturated flow studies, water saturation is commonly used as the sole descriptor for macroscale flow models. However, this approach often results in hydraulic hysteresis in capillary pressure and relative permeability during drainage and imbibition processes. Furthermore, the effects of these behaviors on solute diffusion remain unclear. To address this knowledge gap, we conducted...
Carbon Capture and Storage (CCS) can be realized efficiently and safely by collecting atmospheric carbon dioxide (CO2) and injecting it into basalt formations in a dissolved state by co-injection of CO2 and water. In the actual storage, the collected CO2 may also contain a variety of soluble acidic impurity gases, and co-injection of acidic impurity gases with CO2 can significantly reduce the...
Hydraulic fracturing is an important technique used to stimulate the productivity of shale reservoirs. During the fracturing process, mineral dissolution and precipitation usually occur due to the reuse of the hydraulic fracturing fluid (HFF) in the shale reservoirs. However, the consequences of interactions between the shale matrix and the flow-back HFFs on shale matrix remain unclear. A...
Dynamic imbibition and displacement between the matrix and fractures in shale reservoirs can significantly enhance oil recovery (EOR) following initial depletion. However, the microscopic production characteristics and seepage mechanisms at different pore scales during the dynamic imbibition process remain incompletely understood. In this study, we established an online physical simulation...
Translating fracture statistics to global hydraulic properties in subsurface fractured rocks is a complex but appealing task, as measuring parameters such as permeability can be prohibitively expensive. To tackle this challenge, we developed the finite-size scaling (FSS) hypothesis, drawing inspiration from percolation theory in statistical physics. We created numerous Monte Carlo iterations...
The development characteristics of natural fractures are restricting the efficient development of low permeability reservoirs, but the existing methods not only cannot achieve a quantitative characterization of natural fractures, also cannot achieve quantitative analysis of their effect on permeability. Therefore, based on fractal theory, SEM technology, image processing and permeability...
Abstract
In recent times given the wealth of advancement in scientific research, scientific evidence has shown that CO2 accounts for over 75% of greenhouse gas emission rise between 1990 and 2021 and is projected to further increase due to increasing energy demands in developing countries. Amongst several mitigation tools, The CCS stands out as the most efficient mitigation tool and is...
The current research work mainly focuses on the NaCl-based formation brine, and the influence of different types by formation brine on the salt precipitation have not yet been investigated. Also, the damage effect of local salt crystals on the pore structure and the migration mechanism of salt crystals after precipitation remains unclear. Based on this, this study aims to investigate the...
The Gas Diffusion Layer (GDL) is a critical component that ensures the efficient operation of proton exchange membrane fuel cells, capable of accommodating deformations and pressure differences between cell components. This study proposes a combined method of finite element and stochasticlly reconstruction method for GDL, calculating the stress and stress uniformity inside GDL microstructure...
Permeability and heat transport through building materials ultimately dictates their insulatory performance over a buildings service lifetime. However, characterisation of building materials is challenging because porous building materials are heterogeneous and their macroscopic physical properties (e.g. permeability, thermal, and mechanical) depend on their micro scale characteristics, i.e....
Evaporation from porous media is a key phenomenon in the terrestrial environment and is linked to accumulation of solutes at or near the evaporative surface. It eventually leads to salinization, soil degradation and weathering of building materials, topics with high economic impacts. Although the detrimental effects manifest on different scales from pores to the field, the key to understanding...
In recent years, oil and gas companies operating in regions with high-salinity reservoirs have shown a growing interest in the processes occurring at the pore scale during the displacement of brine with freshwater. This interest is driven by the potential for freshwater injection to alter the physicochemical properties of the rock-fluid system within the pore spaces of the reservoir, thereby...
CO2 Enhanced Oil Recovery (CO2-EOR) is a green and promising technology that not only improves crude oil recovery but also reduces carbon emissions. The micro-pore structure of porous reservoirs significantly influences the effectiveness of CO2-EOR, making research in this area crucial. This study aims at the influence of pore heterogeneity on the non-miscible CO2 displacement and employs a...
Abstract:
Permeability is a measure of flow resistance in porous media. As an important characterization parameter of porous media flow capacity, it is widely used in oil/gas development, filtration analysis, groundwater transport, hydrocarbon recovery and so on. However, on the one hand, the permeability was considered a monodrome function of porosity by many researchers in their...
As a toxic solid waste, the treatment and placement of MSWI fly ash has become a hot topic in society. It was found that the residual aluminum in MSWI fly ash reacted with the alkaline activator to generate hydrogen, which made the material present a pore structure without using the foaming agent. Using MSWI fly ash and coal gangue powder as the main raw materials, geopolymer foam materials...
In our previous work, we investigated the fingering behavior in acid stimulation formations and found that the dissolution patterns in acid stimulation region have an influence on the injection performance. A detailed characterization of the highly heterogeneous wormholes could introduce a large number of gridblocks and subsequently increase the computational burden drastically. In this work,...
Chalk reservoirs, because of their high porosity and very low permeability, represent one of the most interesting cases for carbonate engineering studies. They exhibit complex fluid-rock interactions due to their reactive surfaces and tight porous environment. Re-injection of co-produced water is an attractive strategy for managing the wastewater stream from oil wells, however, the reactive...
Depletion recovery in shale reservoirs after fracturing suffers from a rapid decline in production and low recovery. The CO2 huff-n-puff oil production technology can effectively supplement formation energy, reduce oil-gas interfacial tension and crude oil viscosity, and improve the production of a single well. This technology has good application prospect in enhanced oil recovery of shale...
*Objectives/Scope:
Nowadays, the escalating greenhouse effect is primarily attributed to the excessive emissions of CO2. Geologic sequestration of CO2 and the utilization of CO2 in displacing shale gas during gas production process could be benefit for mitigating CO2 levels. The presence of H2S gas in CO2 waste emissions often poses a challenge due to the potential cost escalation associated...
Coupled thermo-hydro-mechanical (THM) processes play a key role in subsurface use, e.g. geothermal energy, CO2/H2 storage and geological repository. However, understanding these processes in porous media, in which natural fractures can be present and new fractures can be induced, is non-trivial task. The Cohesive Zone Model (CZM), a numerical technique in the framework of the Finite Element...
To enhance the applications of nanoparticles (NPs) in enhancing oil recovery, a crucial aspect is gaining a comprehensive understanding of the transport and detachment mechanisms of oil droplets through a pore throat. A novel, hybrid pore-scale simulation method is proposed, utilizing a combination of Lattice-Boltzmann (LB) and Langevin-Dynamics (LD) approaches to investigate the transport and...
Understanding the intricate pore structure of shale rocks across scales, from nanometres to micrometres, is crucial for optimizing the recovery of natural gas, geothermal energy, and potentially enabling future CO2 sequestration and subsurface hydrogen storage. This study leverages Small Angle Neutron Scattering (SANS), a non-destructive technique, to precisely characterize pore properties in...
Sealing carbon dioxide (CO2) in marine sediments in the form of hydrates presents a promising approach for mitigating greenhouse gas pollution. The captured CO2 often includes other impurity gases, such as nitrogen (N2) and sulfur dioxide (SO2). It is well-established that the release of SO2 carries adverse effects on both human health and the environment. Currently, various flue gas...
Thermal conductivity is a fundamental physical property in porous media, and is critical to various industrial applications. Most existing theoretical models appeal to estimate thermal conductivity with isotropic assumption and the applicable conditions are relatively rigorous. This paper introduces a theoretical model that evaluates the thermal conductivity of fibrous porous media. The model...
In chemical oil drive technology, injecting polymers and surfactants is considered an effective method for adjusting the permeability of reservoir rocks, thereby influencing the flow characteristics of oil and water phases. While the effects of polymers and surfactants on the relative permeability of oil and water have been extensively studied, the impact of gel particles on the oil-water...
The efficiency of nano- and micro-porous materials in absorbing and releasing fluids, like CO$_2$ in geo-storage or water and gas in fuel cells and electrolyzers, depends on their surface wettability. Measuring wettability accurately is complex due to varying dynamic forces, chemical diversity, and surface texture. In situ measurements, which could assess wettability as a local contact angle...
The experimental and numerical study of drainage and primary/secondary imbibition cycles of immiscible displacement are crucial for several practical applications such as the spreading of oil pollutants in soils and groundwater, the in-situ remediation by water flushing, and the enhanced oil recovery (EOR) from reservoir rocks. In order to simulate two-phase flow in pore networks, by now, most...
DuMux (https://dumux.org/) is a general simulation framework (written in C++) with a focus on finite volume discretization methods, model coupling for multi-physics applications, and flow and transport applications in porous media. Its core applications are single and multiphase flow applications in porous media on the Darcy scale, embedded network and fracture models, and free-flow porous...
Hydraulic fracturing in tight oil reservoirs requires injecting large volumes of fracturing fluid into the formation while only a small proportion of fracturing fluid can flow back during the production phase. The retained fracturing fluid will affect subsequent production. We implement an integrated workflow which simulates fracture propagation through a full 3D simulator and seamlessly docks...
Abstract: Tight sandstone reservoir, as unconventional oil and gas resource with abundant quantity, plays a significant role in supporting the growing global demand of energy consumption. However, tight sandstone has complex pore structure and strong heterogeneity, which brings challenges to the development of unconventional hydrocarbon resource. In recent years, the nuclear magnetic resonance...
Abstract: Based on sandstone reservoir samples in Songliao Basin, carbon dioxide displacement of saturated crude oil core experiments were carried out, combined with nuclear magnetic resonance and oil component analysis, to study the mechanism of carbon dioxide oil recovery. The rock samples with proper permeability including medium permeability, low permeability, ultra-low permeability and...
For heavy oil reservoirs buried over 3000 ft, the high pressure would lead to low dryness and expansion difficulty for injected steam. Therefore, they are mostly developed by steam huff and puff, and the EOR methods such as steam flooding and SAGD cannot be used. As a results, the oil recovery could hardly reach 25%.
In order to solve this problem, a method of rapid expansion of steam...
Nanoparticles are widely used in biomedicine, nanoelectronics, energy devices, and Enhancing Oil Recovery (EOR) due to their unique thermodynamic properties and large specific surface area. Recent research highlights the significant impact of the adsorption and diffusion behavior of nanoparticles at the oil-water interface on interfacial properties, particularly interfacial tension. This...
Natural gas hydrate has large reserves and a high level of heat value, which is the strategic commanding point of global energy development. The hydrate reservoirs in the South China Sea are shallowly buried and have low cementation strength. In the process of exploitation for the hydrate reservoirs, workers often face problems such as large sand production, formation instability, and low...
In the development process of edge and bottom water heavy oil reservoir, the existence of edge and bottom water will affect the production effect of the reservoir. Compared with conventional oil reservoirs, edge and bottom water heavy oil reservoirs have a series of production problems, such as short oil production periods without water, rapid rise in water cut, high production cost, and low...
Permeability and capillary pressure curve are important to characterize hydrocarbon-bearing formations. There are several laboratory approaches to estimate such petrophysical properties. Nevertheless, one faces with the range of complications such as uncertainties during laboratory measurements, treating micro- and nano-pore permeability and multi-scale geometry of the pore space, complex...
The vertical variation in permeability is a typical heterogeneity of pore structure in sandstone reservoirs. We thus constructed a millimeter sized layered sandstone, and performed water-alternating-gas (WAG) injection and CO2 foam flooding. After each gas injection, the core was placed vertically for 24 hours and horizontally for 24 hours respectively to study the influence of gravity on...
Low-salinity waterflooding (LSWF) is a promising enhanced oil recovery method that has shown exciting results in various experiments conducted at different scales. With the development of imaging technologies, micro-CT is also employed to investigate LSWF and the synergistic effects of low-salinity brine and polymer. Micro-CT enables the observation of fluid behaviors and the explanation of...
Pore structure features govern the capacity of gas storage and migration in shales and are highly dependent on the types of pores, i.e., interparticle (InterP) pores, intraparticle (IntraP) pores and organic matter (OM)-hosted pores. However, microstructures and fractal features regarding pore types and their respective contributions to permeability have been rarely addressed. Based on SEM and...
There are abundant shale gas resources in China. The technological recoverable resources amount to 21.8 trillion cubic meters, with a proven rate of only 4.8%, and the resource potential is huge. Shale reservoir permeability is very low. It must be fractured to obtain effective productivity. Moreover, the research on the special seepage law of shale gas reservoir is far behind the production...
Due to the essential differences in mass and heat transfer in supercritical water pyrolysis of lump coal, this study focuses on low coalification degree lignite. Employing an organic rock supercritical water reaction apparatus in conjunction with nuclear magnetic resonance and differential scanning calorimetry, we investigated the reaction characteristics of chunk coal supercritical water...
Background, Aims and Scope.
Tight gas resources are abundant and widely distributed, which is an important part of unconventional gas exploration and development. However, the tight sandstone reservoir has the characteristics of low porosity and permeability and micro-fracture development, so the water phase trap damage is more serious in the process of reservoir reconstruction. In addition,...
Contaminated soils typically possess self-healing capabilities, and the ecological concept of emphasizing natural restoration with supplementary artificial reinforcement has gained widespread acceptance. An investigation was conducted into the arsenic pollution status at an abandoned arsenic factory site in southern China. After identifying the spatial distribution characteristics of arsenic...
Abstract: The low viscosity of CO2 and the non-homogeneity of the reservoir can easily cause early gas channeling in the reservoir, which greatly reduces the sequestration and utilization of CO2, so it is important to study the technology of CO2 -WAG flood to expand the wave and volume in the onshore non-homogeneous reservoir. Therefore, we synthesized a chemical agent for CO2 responsive...
Emulsification phenomenon is common in the displacement process of water flooding, surfactant flooding and multiple compound flooding in heavy oil reservoirs. The existence of emulsion can greatly improve the oil displacement efficiency, which has important practical significance for the development of heavy oil reservoirs. However, the description of emulsification phenomenon is basically...
In underground hydrogen storage operations, reservoir rocks often experience periodic pore pressure fluctuations due to annual or more frequent gas extraction and injection cycles. These fluctuations subject the reservoir rocks to cyclic effective stress changes, causing their mechanical and transport behaviours to differ from those under static conditions. However, understanding how porous...
Natural gas hydrates (NGH) are considered as the future clean energy in the era of carbon neutrality [1]. Seepage behaviour of gas-water flow in hydrate-bearing sediment (HBS) and its controlling factors is significant for developing effective production strategies. The flow patterns and relative permeability are two crucial aspects of the study on two phase flow in HBS, which are influenced...
Deep tight gas is an important unconventional natural gas resource, and it is an important target of exploration and development in recent years. Deep tight gas reservoirs are high-temperature, high-pressure, and high-stress with complex gas–water relationships, and its occurrence and flow mechanisms are still unclear, making the simulation of deep tight gas reservoirs still a challenging...
The dissolution of minerals within rock fractures is fundamental to many geological processes. Previous research on fracture dissolution has highlighted the significant role of buoyancy-driven convection leading to dissolution instability. Yet, the pore-scale mechanisms underlying this instability are poorly understood, primarily due to the challenges in experimentally determining flow...
Pore connectivity is a critical factor influencing the migration and production of shale gas (Sun et al., 2017). However, the inherent heterogeneity of shale, characterized by the development of various pore types (Loucks et al., 2012; Ma et al., 2017), renders the detailed and quantitative characterization of shale pore connectivity challenging (Zhao et al., 2020). The advancement of imaging...
Shale gas is a natural gas accumulation mainly located in shale rock series, with adsorption and free state as the main modes of existence, whose content directly affects the cumulative production, gas well’s productivity and life, and is an important index for selection of exploration blocks and reservoir’s evaluation. The determination methods of gas content in shale mainly include...
Due to the law of flow energy consumption in the porous media process is relatively vague, in order to effectively control the energy consumption in the process of oil production by water flooding, a characterization model of oil-water flow energy consumption in porous media during oilfields water flooding development is proposed. The influencing factors of reservoir energy consumption under...
Coreflooding experiments are used regularly for reservoir rock characterization and have been developing in recent years. Investigation of sub-core phenomenon has been a topic of wide interest and estimating sub-core permeability distribution k(x,y,z) is important for that, and also for constructing accurate coreflooding models. This work presents a method for estimating permeability,...
Shale is not only a source rock, but also a reservoir rock, and its porosity evolution characteristics have an important influence on the generation, migration and accumulation of oil and gas in the shale formation. By means of integrated experiments of hydrocarbon generation simulation, conventional-overburden porosity analyses, and field emission-scanning electron microscopy (FE-SEM)...
Sandstone reservoir has good porosity and permeability, which is one of the main oil and gas reservoirs and the focus of oil and gas resources development. Water injec-tion development is the main way of sandstone reservoir development, but with the continuous increase of development time, the water cut of the reservoir is increasing, a large number of reservoirs are in the high water cut...
Saline water evaporation from soil is ubiquitous in many environmental and hydrological processes such as soil water evaporation, vegetation and crop production. It plays an important role on soil salinity influencing soil health and ecosystem functioning. When the salt concentration in soil substantially exceeds its solubility limit as a result of water evaporation, salt crystallization...
Given its immense storage capacity, geological CO2 storage in saline aquifers is regarded as a promising and practical strategy for mitigating anthropogenic CO2 emissions into the atmosphere. During the post-injection phase, where CO2 migration is primarily influenced by buoyant force, local capillary trapping emerges as a crucial mechanism for effective storage. In practical scenarios, saline...
We present a comparison between water-saturated CO2 injection and CO2 injection into an Indiana limestone core. Micro computed tomography (micro-CT) imaging (Figure 1) and mercury intrusion capillary pressure (MICP) measurement (Figure 2) technologies were used to determine the pore size distribution. Results suggest that Indiana limestone consists of three pore sizes: large pores > 200 µm,...
Integrating Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Spectroscopy (EDS), and advanced machine learning techniques like the U-Net model offers new tools and approaches for research in the fields of microstructure analysis and mineralogy. This interdisciplinary approach not only increases the precision of data analysis but also expands the scope of research...
Gas-water two phases flow behavior is fundamental to understand the underground gas exploitation. Due to the limitations that core-scale displacement experiments cannot reveal the evolution of gas-water interface and distribution of gas and water at pore-scale, a visualization study of gas-water two-phase flow at pore-scale using microfluidics was conducted in this study. Both a single...
Abstract: CO2 storage in deep saline aquifers is considered an effective means of mitigating climate change induced by increased CO2 levels in the atmosphere. Additionally, CO2 has a significant impact on enhancing gas recovery (CO2-EGR). Therefore, injecting CO2 into water-bearing gas reservoirs is a win-win way for both CO2 storage and utilization. However, CO2 injection into saline aquifers...
Multistage hydraulic fracture stimulation is commonly used with horizontal well technology as one of key technologies for the economical and effective development of unconventional reservoirs such as tight oil. The applicable method of numerical simulation will provide effective modeling tools for quantitative studies of tight oil reservoir dynamics and performance, fractures and their effects...
Foam is appealing for carbon sequestration due to its remarkable effectiveness in gas-mobility reduction and thus gas sweep improvement (Rossen et al., 2020). Nevertheless, the considerable gas-mobility reduction by foam in the near-well region imposes a concern over foam injectivity. Shear-thinning rheology helps injectivity. Kim et al. (2005) and others show that CO2 foam is strongly shear...
The geological storage of CO2 involves the interaction of non-equilibrated fluids (connate water and injected fluid) which then equilibrate over time. The CO2 phase diagram and solubility of CO2 in water adds significant complexity to this process. Namely, the existence of concentration gradients surrounding fluid-fluid interfaces may impact on wettability or more general on surface...
During fluid displacement in porous rock or soils, as they occur in aquifers or other fluid reservoirs such as CO2 or H2 storage sites or hydrocarbon reservoirs, water films form along the internal pore surface of porous rocks due to its wetting properties and capillarity. Near connate water saturation, these water films dominate the macroscopic flow behaviour as observed e.g. in relative...
Deep saline aquifers are ideal geological storage sites for CO2, containing abundant water and geothermal resources. Injecting CO2 into deep saline aquifers while simultaneously extracting reservoir water can slow down the rise in reservoir pressure, increasing the safety of storage. This approach also extracts water resources to offset the cost gap incurred during the storage process....
In recent years, the extensive using of fossil fuels has led to a substantial release of greenhouse gases, resulting in a pronounced warming trend in the Earth's climate. To mitigate the process of global climate warming, Carbon Capture, Utilization, and Storage (CCUS) projects have gained prominence, with the efficient sequestration of CO2 into geological formations becoming a focal concern....
A larger part of oil in shale formations in Sichuan Basin, China, is volatile oil, which has greater movability compared with other types of oil. However, the production practice showed that the oil production rate declined significantly at the primary production stage (produced by depletion). Therefore, measures of enhanced oil recovery (EOR) should be implemented to acheive effective shale...
The southwest Tarim Depression is an important exploration area in the Tarim Basin. In recent years, an major breakthrough has been made in the substantial increase of exploration reserves, indicating that this area has great exploration and research potential. Collect the Carboniferous-Jurassic reservoir samples from five profiles in the front of Kunlun Mountain in the southwest of Tarim...
The transport of elastic particles (EP) in porous media occurs extensively in groundwater filtration, fluidized beds, and oil field development. However, the pore-throat migration rules and the macro- and micro-matching relationship between EP and porous media require further study. In this work, four mechanism models were designed to conduct microfluidic injectivity experiments. By analyzing...
Permeability is a key parameter determining fluid flow dynamics and production behavior of hydrate-bearing sediments. Figuring out the evolution of dynamic permeability during hydrate phase transition considering media deformation effect is of great significance for the safe and efficient development of hydrate-bearing deposits. In this work, an unstructured pore network with the combination...
The key challenge in polymer flooding for reservoir depth profile control is finding a solution to the contradictory relationship between injectivity and effective displacement. One promising approach is the synthesis of microencapsulated polymers with delayed release characteristics, achieved by encapsulating the polymer within microcapsules. However, the accurate assessment of their targeted...
Glioblastoma (GBM), one of the most common aggressive brain tumours, accounts for more than 50% of primary malignant central nervous system (CNS) gliomas in adults. According to the World Health Organization (WHO) classification [1], brain tumours can be graded from 1 to 4 as pilocytic astrocytoma (PA), diffuse astrocytoma (DA), anaplastic astrocytoma (AA) and GBM in terms of malignancy and...
In recent years, advancements in micro-computed tomography (micro-CT) imaging technology and image processing have significantly enhanced our understanding of the internal structure of rock cores and the distribution of fluids during multiphase flow. Herein, we utilize micro-CT to explore the impact of wettability on fluid flow in a sandstone rock at the pore-scale in combination with relative...
The displacement of residual oil by water flooding in porous media is important in many sandstone reservoirs. Our fundamental understanding of the influence of complex pore geometries of natural sandstones on fluid distribution is still incomplete. To study the formation mechanism and mobilization potential of microscopic discontinuous residual oil, this paper constructs a two-phase flow...
Huff and Puff is an important means to supplement formation energy in the development of unconventional petroleum resources. In this paper, the physical simulation experiments of different injection media huff and puff are carried out by taking the plunged-sample cores of Qinghai oilfield as experimental samples. By means of nuclear magnetic resonance(NMR) technology, the characteristics of...
Introduction
Natural fractures play a crucial role in serving as the primary conduits for seepage in reservoirs, particularly in shale oil reservoirs characterized by ultra-low permeability (Zou et al., 2009; Sun et al., 2023; Bai et al., 2023). Despite the acknowledged significance of these fractures, a notable gap exists in understanding the stress sensitivity of fracture permeability in...
Abstract: Clarifying the injection-production characteristics during CO2 flooding in fractured extra/ultra-low permeability oil reservoirs is significant for further improving oil recovery. This study focuses on the fluid and reservoir characteristics of ultra/low-permeability oil reservoirs in the Changqing Oilfield. Under the conditions of formation temperature and pressure in the target...
The medium-high permeability sandstone reservoir has the advantages of high permeability and porosity, low cementation degree, and strong oil and gas migration ability. The reservoir rocks are mainly composed of clay minerals and fine silty particles. In the long-term water flooding development process, the scouring effect of water will cause clay minerals to fall off and migrate, and the...
Chemical flooding is a very important method to the efficient development of heavy oil reservoir. A clear understanding of the relationship between emulsification characteristics of heavy oil during chemical flooding and test methods that current used to evaluate the properties of chemical flooding agent can be useful for oilfields development of the heavy oil. In this study, the oil-water...
To assess the impact of complex heterogeneities in conglomerate on pore distribution and fluid flow, the effect of heterogeneous debris spatial distribution in conglomerate on CO2 migration under reservoir conditions was studied using X-ray Computed Tomography (X-CT). Four types of conglomerate cores were drilled from the CO2 storage site in the Fushan Depression, China, which include...
The lifetime of a geothermal doublet depends on the time it takes reinjected cold water to reach the hot production well. The spreading of the thermal front as it advances through the reservoir is therefore key to the lifetime of the project. Simulation of thermal dispersion in a heterogeneous reservoir is challenging. Refinement of the grid to incorporate all scales of heterogeneity is...
Numerous studies [1] have been conducted on using surfactant solutions for soil remediation, but their implementation has been limited by the high cost and consumption [2] of surfactant solutions. Moreover, CGA fluids have been shown to be more effective than surfactant solutions in terms of contaminants eliminated per gram of surfactant [3]. An innovative approach to address these challenges...
Although CO2 injection into the geological formations is a promising option to enhance oil recovery, how multiscale pore structures within porous media affects multiphase transport remains poorly understood. This study fully exploits the unique advantages of real-time in-situ visualization of microfluidics to investigate the multiphase flow behavior within micro and nano-pores during both CO2...
Nanofluid injection has been reported as a promising technique to enhance oil recovery in tight reservoirs. However, research pertaining to nanoparticles (NPs) is primarily confined to laboratory experiments, thus the microscopic enhanced oil recovery mechanism behind nanofluid injection remains unclear. Therefore, it is imperative to establish a micro-scale research and analysis methodology...
The fracture-caved porous media contains numerous irregular natural fractures and caves, leading to multiscale pore structures. The geometry of these pore structures can impact the mechanical characteristics of the porous media, and also significantly affect the hydraulic fracture propagation path. This study presents an innovative hydraulic fracturing model designed to simulate the fracture...
Classical synthesis of hydrogen-bonded organic frameworks (HOFs) involve several steps, making challenging the systematic construction of isoreticular HOFs, due to the flexibility and easily disruption of the connection linkages be-tween OLs.1 Herein, we develop an “integrated synthesis-assembly” (ISA) methodology for constructing a series of homologous topological DAT-C6-HOFs (-1, -2 and -3)...
The presence of hard data in geostatistical modeling and optimization problems is important in performing efficient parameter estimation. The hard data at specified points in the model domain serve as a guide in optimizing the unknown parameters to follow the patterns of the hard data. Recently, a novel approach to solving hydrogeologic/reservoir modeling problems has emerged by using deep...
The anaerobic oxidation of methane (AOM) occurring in the surface sediments acts as an important barrier to methane emissions, caused by the reaction between sulphate ions and dissolved methane molecules. However, the current hydrate simulators rarely consider the transport of sulphate and the subsequent AOM reaction. In this study, to investigate AOM effects in hydrate systems, a new...
During fluid production or injection, the reservoir rock undergoes deformation due to the temporal variations of the effective stress field, which can alter the rock porosity and permeability, and further affect the reservoir performance. Previous digital rock models primarily emphasized the quantification of rock properties of the original core, meanwhile often neglecting the alterations of...
Abstract: The shale of the Wufeng-Longmaxi formation in the Sichuan Basin is the preferred layer for shale gas exploration in China, and its petrophysical characteristics are the key to geological and engineering dessert prediction. However, the characteristics and impact mechanisms of its acoustic wave velocity and elastic anisotropy are currently unclear. In this paper, the Wufeng-Longmaxi...
In recent years, the share of unconventional reserves in global oil production has been growing that leads to the development of efficient methods in exploration and development of tight reservoirs. The key features of low-porosity and low-permeability reservoirs are the high heterogeneity of the void space, the ultra-low rock permeability due to the nanoscale pores, and the presence of clays...
The accurate modeling of the three-dimensional structure of porous media is important for the study of the linkage between the microscopic characteristics and the macroscopic physical properties/phenomena. Multi-scale pore structures are widely distributed in nature and industry. However, due to the tradeoff between field of view (FOV) and resolution, it is difficult to obtain high-resolution...
Mass transfer across fracture-matrix interface in a flowing fracture
Mohsen Farhadzadeh, Hamid M. Nick
A direct numerical simulation of the Navier–Stokes equations is utilized to solve two-phase flow in simple fractured porous media [1]. We focus on understanding the impact of fracture flow on the mass transfer between the fracture and porous matrix utilizing a two-dimensional geometry...
Particle migration and plugging are ubiquitous throughout the entire lifecycle of unconsolidated sandstone reservoir development. During the extraction process, particle migration and plugging alter the microscopic characteristics of the reservoir, while the microscopic parameters of the reservoir control particle transport and plugging. This paper utilizes methods such as CFD-DEM,...
The microscopic pore system of hydrate-bearing sediments in the KG Basin was thoroughly described using X-ray computed tomography (XCT), low-field nuclear magnetic resonance (NMR), and N2 gas adsorption (N2GA) technique. Results indicate that the pore types are intricate, exhibiting a wide range of pore shape and limited connectivity. Foraminiferal shells contribute to the presence of certain...
The rapid decline in production from shale gas wells necessitates the implementation of infill drilling and refracturing technologies to effectively utilize the remaining reserves. These techniques are crucial for maintaining long-term stability and increasing production in gas fields. As reservoir depletion occurs and water injection is implemented, geo-mechanical parameters such as reservoir...
The water-based inks with polymeric latex particles used in printing technology deliver prints of superior quality at a low cost and environmental friendly. Via ink formulation and drying processes, the inkjet prints are characterized by a wide color gamut, intense gloss with tonal graduations and excellent mechanical properties.
Our study delves into enhancing the optical performance of...
The overall benefits of geological carbon storage (GCS) depend primarily on CO2 storability and injectability, expressed as saturation and relative permeability, respectively. The effects of GCS schemes on these two properties, the macroscopic response indicators of a two-phase seepage system, are closely related to pore-scale two-phase behaviors. However, the comprehensive effects of...
Groundwater contaminated with dense non-aqueous phase liquids (DNAPLs) such as chlorinated hydrocarbons is difficult to remediate, and the effectiveness of conventional pump treatment techniques is very limited due to its low contaminant solubility. Enhanced in-situ flushing has attracted widespread attention as an alternative to the use of flushing fluid such as cosolvent and gas...
This manuscript presents a comprehensive study on the numerical simulation of gas transport in clay rock using the finite-element method, with a specific focus on the transition of the transport regime from single-phase to two-phase conditions. Our code demonstrates the capability to cover this transition seamlessly, without relying on common approaches such as the use of persistent primary...
Various microorganisms, such as Sulfate Reducing Bacteria (SRB), live in underground reservoirs. The growth rate of microorganisms in a reservoir is highly dependent on various parameters (e.g., the concentration of the nutrients and inhibitors, temperature, pH, and salinity). Especially in case of waterflooded hydrocarbon reservoirs, for large scale modelling of microbial processes, it is...
Currently, µCT has emerged as a valuable tool for analyzing rock samples on a standard core plug scale. Typically utilized in Special Core Analysis (SCAL) as an assessment instrument before the filtration experiment, µCT serves to examine core samples and identify any potential defects, cracks, or heterogeneities that could influence flow behavior during the procedure. Despite the relatively...
There is a growing recognition of the need to reduce the atmospheric concentration of Carbon Dioxide (CO2) to slow the effects of climate change. Many sedimentary basins, which host prolific hydrocarbon resources, are now being reassessed for their potential role as subsurface storage sites, including the East Irish Sea, UK. However, there are implications for subsurface CO2 geological...
The study employed the Washburn capillary rise method to explore the wettability of three conventional cationic, anionic, and nonionic surfactants - CTAB, SDS, and TX-100 - on powders with varying polarities and the resultant behavior of droplets under capillary force. For kaolin, illite, and silica nanoparticles, CTAB's hydrophilic portion interacted with the powder through electrostatic...
In the present era of escalating global energy consumption, there has been a marked shift in the dynamics of energy supply and demand, resulting in significant disparities between these two variables throughout the year. To address this imbalance, energy storage technologies have emerged as a potential remedy to facilitate the integration of renewable energy sources. Among these technologies,...
This study introduces a groundbreaking Autonomous Adaptive Meta Model (AAMM) as an innovative solution to meet the escalating demand for precise and reliable oil prediction rates over a 20-year horizon. By leveraging machine learning algorithms and edge computing techniques, the AAMM dynamically adapts and optimizes its prediction model in real-time, responding to changing oilfield conditions....
Since the beginning of the 21st century, fluid flow in micro-nano space has become a new research hotspot with the rapid development of micro-mechanical systems and bio- engineer-ing. Through quartz capillary and alumina channel, the flow characteristics of gas, water and oil were explored, and the flow characteristics of unconventional oil and gas reservoirs in micro-nano scale were studied....
Deep coal rocks normally have higher gas content compared with shallow to medium-depth coal formations, showing great exploitation potential. However, they generally have complex pore structure and exhibits poor gas transport capacity under high overburden stress. The utilization of massive hydraulic fracturing can effectively release the productivity of deep coal reservoir. Nevertheless, the...
The depth of deep shale gas reservoir is greater than 3500m, the initial liquid production of gas well is large and the flowback rate is high, accounting for the complex gas-water two-phase transport behavior. Besides, due to the characteristics of high pressure and stress in deep shale gas reservoir, the existing transport simulation method is no longer applicable. In this work, a...
Soil salinization influences vegetation, biodiversity, crop production, land-atmosphere interactions, soil health and ecosystem functioning. Quantifying soil salinity is essential to mitigate its determinantal effects (Hassani et al., 2020; 2021). This study utilizes an AI-driven approach for the quantification of soil salinity in EU using a wide range of environmental covariates including...
Active nanofluids are colloidal systems composed of water-based active nanoparticles, garnering significant attention for their outstanding performance in enhancing the recovery efficiency of ultra-low permeability oil reservoirs. Currently, the mechanisms underlying the adsorption and oil film detachment at the oil-water interface by active nanoparticles remain unclear. Simultaneously, the...
The goal of this study lay in the evaluation of the asphaltene deposition on the artificial 2D porous structure of the carbonate rock using high-pressure and high-temperature (HPHT) microfluidic technology. Such technology was utilized to evaluate the behavior of heavy oil quickly and effectively under reservoir conditions, on par with traditional tests. Our workflow started with the designing...
Tianhao Yi, Ran Xu, Chengcheng Chen, Guang Yang*, Jingyi Wu
Institute of Refrigeration and Cryogenics, Shanghai Jiao Tong University, Shanghai 200240, China
*Corresponding author: y_g@sjtu.edu.cn
Abstract
Gas-liquid phase separation based on the porous media is vital for the stable operation of rocket engines in microgravity. To reveal the mechanism of nonisothermal phase separation...
In China, continental shale oil reservoirs are featured with extremely low porosity and permeability, where oil is greatly subjected to solid–liquid adhesion force. The organic matter–oil adhesion force plays a crucial role in shale oil occurrence and movability in shale reservoirs. To effectively characterize the organic matter–oil adhesion force, this paper presents an AFM testing method to...
Geological storage of hydrogen (H2) and carbon dioxide (CO2) is pivotal for a successful energy transition toward a diversified low-carbon economy and a net-zero emission future. The wettability of reservoir rocks in the presence of formation fluids and H2 or CO2 is a controlling factor of gas mobility, residual trapping, and efficient storage. However, the influence of different brine types...
- Objectives/Scope
Steam huff and puff is an important development method for heavy oil reservoirs. An accurate description of the remaining oil distribution after steam huff and puff is crucial for guiding subsequent reservoir development. In this study, a new experimental apparatus was used to simulate the multiple cycles of steam huff and puff process more realistically. The occurrence...
Objectives/Scope（25-75words）
High-flux water displacement is one of the effective methods for low-cost development of mature oilfields. The wettability alteration under high-flux water displacement is the crucial reason for improving displacement efficiency, which makes complex flow characteristic in different pore-throat structures. The objective of this paper is to establish a high-flux...
Water huff-n-puff (WHP) is one of widely used methods to improve oil recovery for tight reservoirs. However, the poor flow-conductivity and low sweep efficiency in matrix also restrict its oil recovery performance. Herein, the N2-water alternating huff-n-puff (NWAHP) was put forward to improve oil recovery at reservoir conditions. firstly, the feasibility of which was confirmed by the...
Unconventional energy sources refer to forms of energy obtained through methods distinct from traditional approaches (Demirbas, 2016). These include not only renewable resources such as solar and wind energy but also less conventional sources like gas hydrate and tar sands. The significance of unconventional energy lies in its potential to diversify energy supplies and reduce dependence on...
The sediment of natural gas hydrate reservoir in the South China Sea is primarily composed of clayey silt, exhibiting characteristics such as loose structure, lack of consolidation, high clay content, and complex pore structure. These features contribute to the complexity of reservoir seepage characteristics, making it challenging for conventional experimental methods to accurately describe...
Multiphase fluid flow in a pore doublet is a fundamental problem and is important for understanding the transport mechanisms of multiphase flows in porous media. During the displacement of immiscible two-phase fluids in a pore doublet, the transport process is influenced not only by the capillary and viscous forces, but also the channel geometry. In this work, a mathematical model and...
The formation space of tight oil reservoir is complex, which develops both matrix pores and micro-fractures, and the classification of matrix pore lower limit has an important influence on the structure and flow characteristics of tight oil reservoirs. In this paper, CT scanning method is used to acquire representative 3D grayscale images of matrix and micro-fracture samples in tight oil...
Shale gas development is relied on long horizontal drilling. But shale is typical formation that wellbore instability often occurs, restricting long horizontal drilling in shale reservoir. Hydration damage is a major trigger of borehole collapse in shale. During drilling process, spontaneous imbibition (SI) is one of main methods of water phase entering into shale. After this invasion,...
Abstract: Wettability plays a crucial role in the percolation capacity of deep tight sandstone reservoirs. Due to great variations in fluid properties, mineral types, and compositions during diagenetic evolution processes, the wettability evolution process and its control mechanism remain unclear, which limits the understanding of hydrocarbon accumulation in deep tight sandstones. In the...
The assessment of perfluorooctanoic acid (PFOA) photocatalytic degradation usually involves tedious pre-treatment and sophisticated instrumentation, making it impractical to evaluate the degradation process in real-time. Here-in, we synthesized a series of lanthanide metal-organic frameworks (Ln-MOFs) with outstanding fluorescent sensing properties and applied them as luminescent probes in the...
