Effect of CO2 and H2O on the behavior of shale gas confined inside calcite [104] slit-like nanopore: a molecular dynamics simulation study

Berghe, Gabriel; Kline, Sydney; Burket, Sarah; Bivens, Laura; Johnson, Denis; Singh, Ramesh P.

doi:10.1007/s00894-019-4180-7

Cited by 18 publications

(7 citation statements)

References 89 publications

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“…The van der Waals and electrostatic interactions that correspond to the adsorption of confined CH 4 molecules, E adsorpation (Figure ), are calculated using eq , where E OH–CH 4 , E OH , and E CH 4 are the interaction energies of the CH 4 –OH group, OH–OH groups, and CH 4 –CH 4 molecules, respectively. , These adsorption energies are normalized by the number of −OH groups on the pore surface for a consistent comparison between the pores of these materials. The normalized adsorption energy increased with the applied pressure in MCM-41 and SBA-15, which justifies the increase in the density of the adsorbed gas layers on the pore surface.…”

Section: Resultsmentioning

confidence: 99%

Probing the Core–Shell Organization of Nanoconfined Methane in Cylindrical Silica Pores Using In Situ Small-Angle Neutron Scattering and Molecular Dynamics Simulations

Mohammed

Liu

et al. 2020

Energy Fuels

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Determining the structure of nanoconfined fluids is essential for predicting the fate of these fluids in subsurface geologic formations with nanoporous features and for engineering novel nanoporous materials for storing compressed gases. In this study, we probe the structure of nanoconfined methane at pressures in the range of 15−100 bar using in situ small-angle neutron scattering (SANS) measurements and molecular dynamics (MD) simulations. The structure of methane is probed in MCM-41 and SBA-15 with cylindrical pores and diameters of 3.3 and 6.8 nm, respectively. In situ SANS measurements and MD simulations showed that the confined methane molecules are organized in a core−shell structure, with the shell arising from the adsorption of methane molecules on the silica surface. The shell thicknesses of the adsorbed deuterated methane (CD 4 ) molecules in MCM-41 obtained by SANS measurements are 1.4

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Section: Resultsmentioning

confidence: 99%

Probing the Core–Shell Organization of Nanoconfined Methane in Cylindrical Silica Pores Using In Situ Small-Angle Neutron Scattering and Molecular Dynamics Simulations

Mohammed

Liu

et al. 2020

Energy Fuels

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“…Furthermore, two distinct reaction pathways were identified that are associated with (1) the chemical adsorption of water at low stress levels and (2) the dissociation of siloxane bonds at high stress levels. More recently, MD simulations in slit-like calcite nanopores were performed by Berghe et al (2019) 282 to examine the structural and dynamic behavior of shale gas in the presence of CO 2 and H 2 O as displacing fluids. These results showed that the shale gas forms a dense layer near pore walls due to the strong interaction forces, and that the weak interaction in the nanoporous core region promotes a displacement of the shale gas by CO 2 and H 2 O, which results in a reduction of absorption capacity.…”

Section: Hydrolytic Weakening Of Fracture Tips Resulting From Hydraul...mentioning

confidence: 99%

Chemical and Reactive Transport Processes Associated with Hydraulic Fracturing of Unconventional Oil/Gas Shales

et al. 2022

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Hydraulic fracturing of unconventional oil/gas shales has changed the energy landscape of the U.S. Recovery of hydrocarbons from tight, hydraulically fractured shales is a highly inefficient process, with estimated recoveries of <25% for natural gas and <5% for oil. This review focuses on the complex chemical interactions of additives in hydraulic fracturing fluid (HFF) with minerals and organic matter in oil/gas shales. These interactions are intended to increase hydrocarbon recovery by increasing porosities and permeabilities of tight shales. However, fluid–shale interactions result in the dissolution of shale minerals and the release and transport of chemical components. They also result in mineral precipitation in the shale matrix, which can reduce permeability, porosity, and hydrocarbon recovery. Competition between mineral dissolution and mineral precipitation processes influences the amounts of oil and gas recovered. We review the temporal/spatial origins and distribution of unconventional oil/gas shales from mudstones and shales, followed by discussion of their global and U.S. distributions and compositional differences from different U.S. sedimentary basins. We discuss the major types of chemical additives in HFF with their intended purposes, including drilling muds. Fracture distribution, porosity, permeability, and the identity and molecular-level speciation of minerals and organic matter in oil/gas shales throughout the hydraulic fracturing process are discussed. Also discussed are analysis methods used in characterizing oil/gas shales before and after hydraulic fracturing, including permeametry and porosimetry measurements, X-ray diffraction/Rietveld refinement, X-ray computed tomography, scanning/transmission electron microscopy, and laboratory- and synchrotron-based imaging/spectroscopic methods. Reactive transport and spatial scaling are discussed in some detail in order to relate fundamental molecular-scale processes to fluid transport. Our review concludes with a discussion of potential environmental impacts of hydraulic fracturing and important knowledge gaps that must be bridged to achieve improved mechanistic understanding of fluid transport in oil/gas shales.

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“…For example, the formation water inside a nanochannel will reduce the nanochannel aperture, which is unfavorable for shale gas migration. In addition, the complex occurrence structure of formation water also complicates the shale gas occurrence, which is inconvenient for reserve assessment. , Therefore, investigating the methane occurrence inside a shale nanochannel with formation water is an important issue for shale gas exploitation.…”

Section: Introductionmentioning

confidence: 99%

“…In addition, the complex occurrence structure of formation water also complicates the shale gas occurrence, which is inconvenient for reserve assessment. 19,20 Therefore, investigating the methane occurrence inside a shale nanochannel with formation water is an important issue for shale gas exploitation. Some experimental studies have been carried out to reveal the effect of formation water on shale gas occurrence.…”

Section: Introductionmentioning

confidence: 99%

Molecular Insight into the Methane Occurrence inside a Shale Nanochannel with Formation Water

et al. 2023

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The occurrence status of shale gas inside a nanochannel of a shale reservoir is crucial for shale gas reserve assessment and exploitation. In this work, adopting molecular dynamics simulations, the methane occurrence inside a shale nanochannel was investigated under different formation water saturations. Moreover, employing three common inorganic minerals including of quartz, calcite, and kaolinite, the influence of mineral hydrophilicity on methane occurrence was also examined. The simulations indicate that there are three occurrence statuses of methane inside nanochannels including a free status located in the internal nanochannel, an adsorption status on mineral and water film surfaces, and a dissolution status inside the water phase. Among them, free-status methane is the dominant contribution to the recoverable reserve assessment and could be feasibly exploited. Without formation water, methane gives two occurrence statuses including an adsorption status on mineral surfaces and a free status. Once the formation water emerges, it will preferentially adsorb onto the mineral surface to form a water film. With the increase of formation water saturation, the proportions of free-status and dissolution-status methanes increase, while the proportion of adsorption-status methane decreases. In three mineral nanochannels with hydrophilicity orders of quartz > calcite > kaolinite, the proportion of adsorption-status methane follows the order of kaolinite > calcite > quartz, and free-status methane gives the order of kaolinite ≈ quartz > calcite. The underlying mechanisms of these occurrence features were discussed at length from the view of microscopic interactions among mineral surfaces, water, and methane. Our work presents the methane occurrence structure inside a shale nanochannel, and the discussion of the three methane occurrence statuses could provide fundamental data and theoretical guidance for shale gas reserve assessment and exploitation.

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Effect of CO2 and H2O on the behavior of shale gas confined inside calcite [104] slit-like nanopore: a molecular dynamics simulation study

Cited by 18 publications

References 89 publications

Probing the Core–Shell Organization of Nanoconfined Methane in Cylindrical Silica Pores Using In Situ Small-Angle Neutron Scattering and Molecular Dynamics Simulations

Probing the Core–Shell Organization of Nanoconfined Methane in Cylindrical Silica Pores Using In Situ Small-Angle Neutron Scattering and Molecular Dynamics Simulations

Chemical and Reactive Transport Processes Associated with Hydraulic Fracturing of Unconventional Oil/Gas Shales

Molecular Insight into the Methane Occurrence inside a Shale Nanochannel with Formation Water

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