New Coupled Apparent Permeability Models for Gas Transport in Inorganic Nanopores of Shale Reservoirs Considering Multiple Effects

Wang, Shan; Shi, Juntai; Wang, Ke; Sun, Zheng; Zhao, Zhengfu

doi:10.1021/acs.energyfuels.7b02948

Cited by 17 publications

(14 citation statements)

References 51 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In contrast, on the basis of relative mature theory and reasonable assumptions, a lot of analytical models have been proposed to capture multiple gas flow mechanisms or fluid storage modes inside both shale organic/inorganic matrix, encompassing gas adsorption, surface diffusion, water distribution features, wall roughness (Sheikholeslami et al, 2020(Sheikholeslami et al, , 2021a(Sheikholeslami et al, , 2021b. Notably, each theoretical model has its own applicable criterions or suitable conditions and may fail to generate desirable results, particularly at nanoscale pores (Bao et al 2017a(Bao et al , 2017bWang et al 2017). As a result, the analytical models, coupling classic theories and multiple key flow mechanisms, inevitably suffer limitations for practical application toward realistic cases.…”

Section: Introductionmentioning

confidence: 99%

Nanoconfined methane flow behavior through realistic organic shale matrix under displacement pressure: a molecular simulation investigation

Sun

Huang

et al. 2021

J Petrol Explor Prod Technol

Self Cite

View full text Add to dashboard Cite

Academic investigations digging into the methane flow mechanisms at the nanoscale, closely related to development of shale gas reservoirs, had attracted tremendous interest in the past decade. At the same time, a good understanding of the complex essence remains challenging, while the broad theoretical scope, as well as application value, possesses great attraction. In this work, with the help of molecular dynamics methods nested in LAMMPS software, a fundamental framework is established to mimic the nanoconfined fluid flow through realistic organic shale matrix. Denoting evident discrepancy with existed contributions, shale matrix in this work is composed of specific number of kerogen molecules, rather than simple carbon-based nanotube. Recently, promotion efforts have been implemented in the academic community with the use of kerogen molecules, however, gas flow simulations are still lacking, and the pore shape in the current papers is always hypothesized as slit pores. The pore-geometry assumption seriously conflicts with the general observation phenomenon according to the advanced laboratory experiments, such as SEM image, AFM technology, that the organic pores tend to have circular pore geometry. In order to fill the knowledge gap, the circular nanopore with desirable pore size surrounded by kerogen molecules is constructed at first. The organic nanopore with various thermal maturity can be obtained by altering the kerogen molecular type, expecting to achieve more physically and theoretically similar to the realistic shale matrix. After that, methane flow simulation is performed by utilization of non-equilibrium molecular dynamics, the methane density as well as velocity distribution under different displacement pressures are depicted. Furthermore, detailed discussion with respect to the simulation results is provided. Results show that (a) displacement pressure acts as a dominant role affecting methane flow velocity and, however, fails to affect methane density distribution, a behavior mainly controlled by molecular–wall interactions; (b) the velocity distribution feature appears to be in line with the parabolic law under high atmosphere pressure, which can be attributed to small Knudsen number; (c) the simulation time will be prolonged with larger displacement pressure imposed on nanoconfined methane. Accordingly, this work can provide profound basis for accurate evaluation of nanoconfined gas flow behavior through shale matrix.

show abstract

Section: Introductionmentioning

confidence: 99%

Nanoconfined methane flow behavior through realistic organic shale matrix under displacement pressure: a molecular simulation investigation

Sun

Huang

et al. 2021

J Petrol Explor Prod Technol

Self Cite

View full text Add to dashboard Cite

show abstract

“…Li et al , established a mathematical model to quantify the thickness of the water film at certain relative humidity conditions and demonstrated that the water film decreases the flow volume of methane in hydrophilic nanopores. On this basis, Sun et al, Wang et al, and Li et al developed corresponding permeability models for gas flow in hydrophilic nanopores by accounting different factors such as cross-sectional shapes, confinement effect, and moisture content. They pointed out that initial water saturation significantly decreases the effective permeability of methane.…”

Section: Introductionmentioning

confidence: 99%

“…pointed out that the permeability of methane flow in hydrophilic nanopores reduces about 15–30% with 30% water saturation. Although considerable progresses have been achieved on gas–water two-phase flow in nanopores by these analytical studies, most of the current flow models − merely considered the ideal super-hydrophilic nanopores, where the water film is assumed as the extension of the walls. The effect of water film on the gas–walls interactions are universally neglected as well.…”

Section: Introductionmentioning

confidence: 99%

Two-Phase Transport Characteristic of Shale Gas and Water through Hydrophilic and Hydrophobic Nanopores

Fan

et al. 2020

Energy Fuels

View full text Add to dashboard Cite

Previous attempts to characterize shale gas transport in nanopores are not fully successful due to the fact that the presence of water within shale reservoirs is generally overlooked. In addition, shale is known as a wettability-varying (hydrophilic and hydrophobic) rock depending on various components and maturity grades. Herein, toward this end, we performed a comprehensive study about two-phase transport characteristic of shale gas and water through hydrophilic and hydrophobic nanopores by integrating the molecular dynamics (MD) simulations and analytical models. Using MD simulations, we showed that water molecules prefer to accumulate at the walls (water film) in hydrophilic nanopores while form the water cluster at the center region of hydrophobic nanopores, which significantly alters the shale gas transport behavior. For hydrophilic nanopores, the existence of water film weakens the gas–walls collisions (slip effect), resulting in a viscosity dominant transport mechanism. In contrary, shale gas transport in hydrophobic nanopores is mainly contributed by slip effect where the gas–gas collisions (viscosity) is abated by the water cluster. On this basis, we proposed an analytical model to quantitatively depict the shale gas transport behavior in moist nanopores, which is well verified by MD simulations results. Particularly, according to our flow model, the gas transport capacity decreases to only 15% when mixing with 50% water molecules for both hydrophilic and hydrophobic nanopores, which would be greatly overestimated by traditional models neglecting the presence of water molecules. The deep insights gained in this work will further the exploitation and development of shale reservoirs.

show abstract

“…241 To accurately estimate formation properties and shale gas production forecasts, various studies report permeability models coupled to mechanical effects. [242][243][244][245][246][247] Liehui, et al 238 compared the different models and found that the Palmer and Mansoori 248 model is suitable to describe permeability variations of a shale gas well over its entire production life span. Because of gas desorption in shale gas reservoirs, shale matrix shrinkage progressively occurs but particularly during the late production stage which can lead to an increase in permeability.…”

Section: Review Energy and Environmental Sciencementioning

confidence: 99%

The role of supercritical carbon dioxide for recovery of shale gas and sequestration in gas shale reservoirs

Lyu

Tan

et al. 2021

Energy Environ. Sci.

124

View full text Add to dashboard Cite

show abstract

New Coupled Apparent Permeability Models for Gas Transport in Inorganic Nanopores of Shale Reservoirs Considering Multiple Effects

Cited by 17 publications

References 51 publications

Nanoconfined methane flow behavior through realistic organic shale matrix under displacement pressure: a molecular simulation investigation

Nanoconfined methane flow behavior through realistic organic shale matrix under displacement pressure: a molecular simulation investigation

Two-Phase Transport Characteristic of Shale Gas and Water through Hydrophilic and Hydrophobic Nanopores

The role of supercritical carbon dioxide for recovery of shale gas and sequestration in gas shale reservoirs

Contact Info

Product

Resources

About