Modeling of multi-scale transport phenomena in shale gas production — A critical review

Application of upscaling methods for fluid flow and mass transport in multi-scale heterogeneous media: A critical review

As the typical unconventional reservoir, shale gas is believed to be the most promising alternative for the conventional resources in future energy patterns, attracting more and more attention thro...

Transport of Shale Gas in Microporous/Nanoporous Media: Molecular to Pore-Scale Simulations

Nanoconfined fluids (NCFs), which are confined in nanospaces, exhibit distinctive nanoscale effects, including surface effects, small-size effects, quantum effects, and others. The continuous medium hypothesis in fluid mechanics is not valid in this context because of the comparable characteristic length of spaces and molecular mean free path, and accordingly, the classical continuum theories developed for the bulk fluids usually cannot describe the mass and energy transport of NCFs. In this Perspective, we summarize the nanoscale effects on the thermodynamics, mass transport, flow dynamics, heat transfer, phase change, and energy transport of NCFs and highlight the related representative works. The applications of NCFs in the fields of membrane separation, oil and gas production, energy harvesting and storage, and biological engineering are especially indicated. Currently, the theoretical description framework of NCFs is still missing, and it is expected that this framework can be established by adopting the classical continuum theories with the consideration of nanoscale effects.

Nanoconfined Fluids: What Can We Expect from Them?

Understanding the adsorption mechanism of CO2/CH4 in kaolinite clay is essential for the carbon dioxide geological sequestration and enhanced gas recovery in shale reservoirs. In the present work, grand canonical Monte Carlo simulations were employed to investigate the mechanism of competitive adsorption of CO2/CH4 in kaolinite clay. The effects of pore size (1–6 nm), pressure (0.1–30 MPa), temperature (298–378 K), and moisture content (0–0.122 g/cm3) on the adsorption behaviors of pure CH4 and CO2/CH4 mixture were explored in-depth. Specifically, two adsorption layers, i.e., strong and weak adsorption layers, in kaolinite slitlike micropore under high pressure condition have been observed. It was found that pore size and pressure have great effects on the gas adsorption mechanism in kaolinite. The two adsorption mechanisms including monolayer adsorption and micropore filling under high pressure or small pore size conditions were discussed. In addition, simulation results showed that CO2 has much stronger...

Adsorption Mechanism of CO2/CH4 in Kaolinite Clay: Insight from Molecular Simulation

Shale gas is becoming an increasingly promising alternative energy resource because of its high efficiency and environment-friendly characteristic. The amount of adsorbed gas on the shale matrix surfaces and dissolved gas in the shale matrix bulk is the dominant factor in the long-term productivity of shale reservoir. Although experimental measurements have been extensively carried out to investigate the gas adsorption and diffusion properties in the shale matrix, they cannot provide the detailed information on the microscopic transport mechanism of shale gas during the gas production process. Molecular simulation can accurately visualize the gas adsorption/desorption and diffusion processes in the shale matrix. In the present study, the recent research advances of molecular simulation on gas adsorption/desorption and diffusion in the shale matrix are reviewed. Firstly, the density functional theory (DFT) for shale gas molecule desorption/adsorption on the surface of the matrix crystal is illustrated. Then, the grand canonical Monte Carlo (GCMC) method predicting the amount of shale gas desorption/adsorption in the shale matrix crystal is introduced. Finally, molecular dynamics simulation (MD) for gas diffusion in the shale matrix is elucidated. Further developments of the molecular simulation method in shale gas production are also discussed.

Review of Molecular Simulation Method for Gas Adsorption/desorption and Diffusion in Shale Matrix

In the originally published article version the family name of first author WANG Hui was misspellt “WAND” The original article has been corrected

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Bo Yu

Papers

Modeling of multi-scale transport phenomena in shale gas production — A critical review

Review of Molecular Simulation Method for Gas Adsorption/desorption and Diffusion in Shale Matrix

Erratum to: Review of Molecular Simulation Method for Gas Adsorption/desorption and Diffusion in Shale Matrix