Article
Geosciences, Multidisciplinary
K. Sawayama, T. Ishibashi, F. Jiang, T. Tsuji
Summary: This study investigated changes in permeability, resistivity, and their respective relationships at elevated stress through numerical simulations and microscopic flow analysis. The findings suggest that the permeability evolution of fractures can be described by resistivity changes, independent of fracture geometric characteristics.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Chemistry, Physical
Kawthar Adewumi Babatunde, Berihun Mamo Negash, Muhammed Rashik Mojid, Tigabwa Y. Ahmed, Shiferaw Regassa Jufar
Summary: Molecular simulation is widely used in adsorption studies, but realistic modeling and preparation of shale remains a challenge. Existing studies often use single components to represent shale surfaces, lacking the heterogeneity and mineral diversity of actual shale surfaces. The proposed molecular shale model exhibits higher adsorption capacity and surface area, providing a more accurate understanding of adsorption behaviors.
APPLIED SURFACE SCIENCE
(2021)
Article
Geochemistry & Geophysics
Jianfa Wu, Xuefeng Yang, Shan Huang, Shengxian Zhao, Deliang Zhang, Jian Zhang, Chunyu Ren, Chenglin Zhang, Rui Jiang, Dongchen Liu, Qin Yang, Liang Huang
Summary: This study constructed molecular models of nanopores for major rock constituents in deep shale and simulated the microscopic adsorption behavior of methane. The effects of rock constituents on methane adsorption were discussed. The study elucidated the discrepancies in microscopic water distribution characteristics between illite and kerogen nanopore models, revealed the effects of water on methane adsorption and its underlying mechanisms, and elaborated on the competitive adsorption characteristics between water and methane. The results showed a similar trend in the microscopic distribution of methane between different shale rock constituents. Illite and kerogen slit pores had no significant difference in methane adsorption capacity. The adsorption capacity per unit mass of kerogen was greater than that of illite due to the smaller molar mass of the kerogen skeleton and its large intermolecular porosity. Illite had a greater affinity for water than methane. With increasing water content, water molecules preferentially occupied the high-energy adsorption sites and then overspread the entire pore walls to form water adsorption layers. Methane molecules were adsorbed on the water layers, and methane adsorption had little effect on water adsorption. Kerogen was characterized as mix-wetting. Water molecules were preferentially adsorbed on polar functional groups and gathered around to form water clusters. In kerogen with high water content, methane adsorption could facilitate water cluster fusion and suppress water spreading along pore walls. In addition to adsorption, some water molecules dissolved in the kerogen matrix.
Article
Energy & Fuels
Hanyu Zhang, Menatalla Ahmed, Jin-Hui Zhan
Summary: This paper introduces the basic knowledge and applications of molecular simulation in analyzing kerogen, and reviews the molecular simulation studies of kerogen's structure, geological processes, interactions with minerals and shale gases, and pyrolysis. Future research directions are also proposed.
Article
Computer Science, Software Engineering
Javier E. Santos, Alex Gigliotti, Abhishek Bihani, Christopher Landry, Marc A. Hesse, Michael J. Pyrcz, Masa Prodanovic
Summary: MPLBM-UT is a lattice-Boltzmann library specifically designed for single- and two-phase flow simulations in porous media. It provides a comprehensive set of tools and interfaces that allow users to perform simulations and visualize results with ease.
Article
Engineering, Environmental
Jie Liu, Yongfei Yang, Shuyu Sun, Jun Yao, Jianlong Kou
Summary: This study investigates the flow behavior of multicomponent shale oil in realistic kerogen channels using molecular dynamic simulation. The results show that the flow of shale oil exhibits peristaltic behavior due to the influence of kerogen branched chains. The heavy component forms adsorbed layers, while asphaltene molecules cluster in bulk phase. Increasing driving force and temperature enhance shale oil flow.
CHEMICAL ENGINEERING JOURNAL
(2022)
Article
Engineering, Environmental
Wei Li, Lee A. Stevens, Bo Zhang, Dingye Zheng, Colin E. Snape
Summary: Moisture has a critical impact on shale gas resource estimation by affecting gas adsorption and pore structure. It reduces the methane adsorption capacity of kerogen mainly by occupying and blocking the pore volume rather than competing directly with methane for sorption sites.
CHEMICAL ENGINEERING JOURNAL
(2023)
Article
Energy & Fuels
Guenther Glatz, Saad Alafnan, Raoof Gholami, Arshad Raza, Mohamed Mahmoud, Khaled Al-Azani, Abeeb Awotunde
Summary: This study investigates the adsorption characteristics of shale under various pressure and temperature conditions and evaluates the predictive power of different theoretical adsorption models. The results suggest that the Langmuir, Toth, and Langmuir-Freundlich models are suitable for single component adsorption, while the Toth and LRC models are capable of capturing acceptable binary adsorption behavior.
Article
Engineering, Geological
K. Sawayama, T. Ishibashi, F. Jiang, T. Tsuji, Y. Fujimitsu
Summary: This study investigates simultaneous changes in hydraulic and geophysical properties of natural rock fractures under increasing normal stress, and correlates the property changes through coupling experiments and digital fracture simulations. It is found that electrical resistivity is linked with permeability and flow area, while elastic wave velocity is roughness-dependent.
ROCK MECHANICS AND ROCK ENGINEERING
(2021)
Article
Energy & Fuels
Wei Li, Lee A. Stevens, Bo Zhang, Dingye Zheng, Colin E. Snape
Summary: Combining molecular simulation and experimental results provides a more detailed understanding of gas sorption in kerogens than either approach in isolation. The main differences between kerogens affecting methane adsorption are porosity and chemical functionality, but it has not been clearly stated which one is the key control. The study concludes that micropore volume in kerogens is the key control for methane adsorption, and the differences in surface functionality have a negligible effect on methane adsorption.
INTERNATIONAL JOURNAL OF COAL GEOLOGY
(2022)
Article
Engineering, Petroleum
Sheng Peng, Pavel Shevchenko, Priyanka Periwal, Robert M. Reed
Summary: This study investigated the process of water-oil displacement in shale through a comparative study of three different shale samples. The findings highlighted the importance of pore structure and wettability on oil recovery and residual oil distribution, providing important insights for improved oil recovery strategy in shale. The integrated imaging and imbibition technique used in this study offers a new approach for further research on improved oil recovery in shale.
Article
Engineering, Environmental
Saeed Babaei, Hasan Ghasemzadeh, Stephane Tesson
Summary: Accurately predicting gas adsorption in shale gas is crucial for estimating production capacity and optimizing extraction processes. The complex nature of shale reservoirs poses significant challenges in understanding the mechanism of methane adsorption. Through the use of a nanocomposite shale model and hybrid simulations, the study investigates methane adsorption in rigid and flexible shale models under different conditions. The results highlight the influence of factors such as kerogen flexibility, pore width, moisture content, temperature, and pressure on fluid behavior.
CHEMICAL ENGINEERING JOURNAL
(2023)
Article
Engineering, Environmental
Sen Wang, Xinyu Yao, Qihong Feng, Farzam Javadpour, Yuxuan Yang, Qingzhong Xue, Xiaofang Li
Summary: This study investigates the competitive adsorption between CO2 and hydrocarbon components in shales, as well as the recovery mechanisms of CO2 huff-n-puff in kerogenic circular nanopores. The study reveals that different pore geometries and compositions significantly impact gas adsorption and recovery behaviors, highlighting the importance of using realistic shale kerogen models. Additionally, increasing pore size improves gas recovery during pressure drawdown but limits the effectiveness of CO2 injection, leading to an overall increase in gas recovery and CO2 sequestration efficiency.
CHEMICAL ENGINEERING JOURNAL
(2021)
Article
Energy & Fuels
T. R. Zakirov, M. G. Khramchenkov
Summary: This paper investigates the effect of pore space heterogeneity on off-diagonal permeability tensors. The results show that heterogeneity significantly affects the sensitivity of permeability components to different driving forces and boundary conditions, and also influences the symmetry of the permeability tensor.
JOURNAL OF PETROLEUM SCIENCE AND ENGINEERING
(2022)
Article
Chemistry, Analytical
Wang Xinmin, Wang Qing, Pan Shuo, Cui Da, Sun Shipeng, Wu Chunlei, Chang Hongyun
Summary: In this study, ReaxFF molecular dynamics simulations were used to investigate the reaction mechanism and product distribution during the thermal evolution of Fushun oil shale kerogen. The simulations were conducted at different heating rates, and the results showed that kerogen pyrolysis is mainly an internal molecular change. The pyrolysis process produces large volumes of shale oil and gas, which can be utilized in industrial applications.
JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
(2023)