Natural gas (main methane CH4) hydrates are such a prospective energy resource that feeds the global energy demand. Depressurization has been proved the most economical method for CH4 hydrate exploitation. However, micro characteristics of hydrate distribution and fluid migration in porous media are still lacking for efficient CH4 hydrate exploitation. In this work, morphologies of CH4 hydrate...
Shale resources are massive, controversial, and provide an increasing share of global energy with a broad group of stakeholders in academia, industry, and government. CO2 injection is promising for enhancing shale resource recovery due to its high mobility in tight porous media and strong extraction capacity for hydrocarbons. Meanwhile, the injected CO2 can be sequestered in the reservoir to...
For a successful transition towards renewable energy resources, hydrogen is playing an increasingly significant role. In order to have a sufficient amount of hydrogen available to meet the demand, it has to be stored in suitable facilities. The storage of hydrogen in subsurface porous media is considered to be a viable option. The most promising sites are currently used as underground gas...
Hydro-geochemical processes such as transport-induced mineralization are important processes governing the evolution of many systems in the context of energy-related exploitation of the sub-surface. These processes can lead to an alteration of permeability, diffusivity and other physical characteristics of the rock matrix that can have significant effects on subsurface solute and gas...
Surface charging at immiscible liquid-liquid interface is essential to the emulsion stability, surfactant adsorption, and various engineering applications such as drug delivery and mineral flotation. However, droplet electrophoresis, as a widely-used electrokinetic method to measure the surface charge density, has various limitations in physical modeling and sample preparation. In this work,...
Polymer nanogels, crosslinked polymer particles, have attracted increasing interest in Enhanced Oil Recovery (EOR) field. However, it is still unclear that how to properly utilize nanogels to reach their full potential in oilfields because the transport mechanisms of nanogels in porous media are not well understood so far. In this work, we synthesized a fluorescent nanogel and visualized the...
Geothermal fluids are often loaded with mineral and organic particles in suspension, various additives, microorganisms, heavy metals, etc. These compounds result in significant problems on the sustainability of production and the maintenance of injectivity in the short term and, in the long term, on the stability and continuity of the resource. As the migration and deposit of fines concern...
Pore-blocking efficiency is a key factor when dilute and stable emulsions are used as flow diversion agents to increase oil recovery and reduce water mobility in preferential flow paths. Emulsion plugging occurs when droplets of the dispersed phase are trapped in the pore throats as they flow through porous media. The droplet capture phenomenon is highly dependent on the drop-to-pore size...
The motivation for the present study stems from visualizations of the PTFE distribution in the gas diffusion layer (GDL) of Proton Exchange Membrane Fuel Cell (PEMFC). The GDL is a fibrous carbon layer treated with polytetrafluoroethylene (PTFE), by drying a layer saturated with a solution of PTFE particles, to improve hydrophobicity1. During the fabrication, internal surfaces appears to be...
The use of foam technology is a potential solution to control gas mobility in highly heterogeneous reservoirs. However, achieving stable CO2-foams under reservoir conditions can be challenging since the high solubility in water of supercritical CO2 enhances coarsening and coalescence of confined bubbles. Coarsening is characterized by the evolution of foam structure due to gas diffusion...
CO2 injection in deep aquifers is a way to perform CO2 storage, but it requires an impervious overlying formation called caprock to avoid any catastrophic leakage. The post-injection CO2 bubbles accumulate rapidly at the aquifer-caprock interface, creating a multiphasic situation and drying the caprock interface. Due to the thinness of the pore size distribution, this drying can lead to the...
CO2 injection into the geological formations is a promising option to enhance oil recovery while simultaneously contributing to carbon storage. Conventional core tests provide critical insights but still leave ambiguous transport mechanisms due to the limitation of real-time visualization. This study aims to directly observe the multiphase flow behaviors and phase change in CO2 injection at...
Deep saline aquifers are promising CO2 geological sequestration sites with wide distribution and large storage capacity. Pilot projects have shown that the injection of CO2 into saline aquifers can lead to brine drying and salt precipitation, and eventually injectivity reduction. The interplay between gas injection, brine drying and salt precipitation determines the distribution of resulted...
Sol-gel processes have been widely used as an easy way to form stable thin films of inorganic polymeric materials for ceramics, coatings and more recently to enhance the mechanical properties of porous media. The latter is extremely important for the preservation of our stone cultural heritage, where several types of gel treatment have been proposed to consolidate damaged porous stones [1-3]....
Darcy’s law describes the flow of Newtonian fluids through bulk porous media as the product of the applied pressure difference, the fluid’s viscosity and the medium’s permeability. Brinkman extended Darcy’s law with a viscous stress term, thereby enabling boundary conditions to the flow field at the surface of the medium. The validity of Brinkman’s term, and the value of its effective...
Nanogel particles are emerging as an attractive additive for multiphase displacement control in natural processes and engineering systems. However, different from microgel or inorganic nanoparticles, the performance and mechanism of nanogel particle suspensions have not been well explored yet. In this study, we discovered a novel nanogel-in-oil colloidal state formed naturally with ideal...
We are interested in the transport of solid particle suspensions in porous media, which are important in many applications, in soil mechanics, in filtering operations... etc. . The accumulation of these particles is indeed often undesirable because it leads to a reduction of the permeability and sometimes to a complete clogging of the medium. Different types of clogging (geometrical, bridging,...
Growth mechanisms of CO2 hydrates in pores dictate the capacity, injection rates, and long-term security of sequestered carbon. We reveal a previously unrecognized reactive transport mechanism dictating hydrate growth in pores: capillarity. Hydrate crystals, having superhydrophilic surfaces (θ~0°), form a secondary microporous medium (~ 100 nm pores) within individual lithologic pores (~ 10 to...
