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
Geosciences, Multidisciplinary
Wei Guo, Xiaowei Zhang, Rongze Yu, Lixia Kang, Jinliang Gao, Yuyang Liu
Summary: This study comprehensively considers the influence of multiple physical phenomena on the flow of shale gas in nano-scale pores and establishes an apparent permeability model. The research results show that the contributions of different physical phenomena to permeability depend on pore pressure and pore size, and the presence of real gas effect and confinement effect significantly affect permeability. This study is of great significance for accurately measuring the permeability of shale matrix and evaluating the productivity of shale gas horizontal wells.
FRONTIERS IN EARTH SCIENCE
(2022)
Review
Energy & Fuels
Kawthar Adewumi Babatunde, Berihun Mamo Negash, Shiferaw Regassa Jufar, Tigabwa Yosef Ahmed, Muhammed Rashik Mojid
Summary: This study reviews the current research on adsorption models in shale formation, emphasizing the importance of finding a model that accurately describes the adsorption mechanism. It also analyzes the controlling factors of adsorption mechanism and their interactions. The most commonly used adsorption model is Langmuir, but it does not fully represent the characteristics of shale formation.
JOURNAL OF PETROLEUM SCIENCE AND ENGINEERING
(2022)
Article
Chemistry, Physical
Suyu Yang, Beibei Zhang, Xiaofan Zheng, Guohui Chen, Yiwen Ju, Bo-Zhen Chen
Summary: The study investigated the adsorption mechanisms of CH4, CO2, and H2O molecules on various shale surfaces using density functional theory. Results showed that the Al&Mg-doped illite surface exhibited the strongest adsorption ability, with H2O having the highest adsorption capacity among the three molecules.
SURFACES AND INTERFACES
(2021)
Article
Energy & Fuels
Humera Ansari, Elena Rietmann, Lisa Joss, J. P. Martin Trusler, Geoffrey Maitland, Ronny Pini
Summary: The optimization of shale gas production still faces challenges, with uncertainty in procedures accounting for gas adsorption being a key issue; research shows that adsorption does not necessarily guarantee higher gas production; by using a proxy reservoir model to evaluate scenarios of gas injection for improved recovery, it is found that partial pressure and competitive adsorption enhance gas production, but there is a trade-off between methane recovery and CO2 storage.
Article
Engineering, Marine
Youzhi Wang, Wei Li, Xiandong Wang, Zhiguo Wang, Weiqi Ma, Yanping Zhu, Mengdi Sun, Bo Liu, Lijuan Cheng, Xiaofei Fu
Summary: This study analyzed the pore structure of shale from the Ziliujing Formation in the Sichuan Basin. The results showed that different types of shales have different mineral compositions and pore characteristics. Clay minerals have a significant impact on pore distribution, while TOC has a relatively small effect. This study is important for understanding the occurrence of shale oil in different reservoir facies and provides a guideline for future exploration in the area.
JOURNAL OF MARINE SCIENCE AND ENGINEERING
(2023)
Article
Chemistry, Multidisciplinary
Kouqi Liu, Mehdi Ostadhassan, Ho Won Jang, Natalia V. Zakharova, Mohammadreza Shokouhimehr
Summary: In this study, the fractal dimensions of several shale samples were evaluated and compared using nitrogen adsorption isotherms. The Frenkel-Halsey-Hill, Neimark, and Wang-Li models can all be applied for fractal dimension characterization of shale samples. However, as the micropore surface area or volume increases in the samples, the differences in fractal dimensions among these models also increase.
Article
Engineering, Environmental
Jingyue Sun, Cong Chen, Wenfeng Hu, Jingwei Cui, Lanlan Jiang, Yu Liu, Yuechao Zhao, Weizhong Li, Yongchen Song
Summary: The CO2 sequestration and enhanced gas recovery (CS-EGR) technology is effective in alleviating the greenhouse effect and energy crisis, especially in understanding the competitive adsorption behavior of CO2 and CH4 in shale matrix. The graphene-MMT heterogeneous surface pore model plays a vital role in studying the competitive adsorption features.
CHEMICAL ENGINEERING JOURNAL
(2021)
Article
Engineering, Petroleum
Runxuan Sun, Ke Xu, Tianjia Huang, Dongxiao Zhang
Summary: Molecular diffusion is the main mass transport mechanism in nanoporous media with <10-nm pores, and a novel geometric model is proposed to study fluid behavior. The distortion of the pore structure influences the diffusion of methane and its mixtures.
Article
Energy & Fuels
Do Yoon Moh, Hongwei Zhang, Shihao Wang, Xiaolong Yin, Rui Qiao
Summary: The study investigates the soaking step of CO2 Huff-n-Puff in a single, 4 nm-wide calcite pore using molecular dynamics simulations. The results show that CO2 molecules can be adsorbed on pore walls and diffuse along the walls or into the pore's interior as free molecules. The movement of adsorbed and free CO2 molecules inside the pore obeys a specific scaling law, highlighting the importance of surface adsorption in the storage and transport of CO2 in unconventional oil reservoirs.
Article
Energy & Fuels
Kang Yang, Junping Zhou, Xuefu Xian, Yongdong Jiang, Chengpeng Zhang, Zhaohui Lu, Hong Yin
Summary: The study investigated the impact of supercritical CO2-water exposure on the adsorption characteristics of shale, revealing that increasing exposure pressure and decreasing exposure temperature resulted in a gradual decrease in CH4 and CO2 adsorption capacity in shale due to alterations in mineral composition and pore structure. The study also found that the selectivity factor of CO2 to CH4 decreased with increasing exposure pressure and decreasing temperature, indicating the feasibility of CO2-enhanced shale gas recovery and sequestration even after exposure to ScCO2-water.
Review
Energy & Fuels
Yijie Xing, Xianming Xiao, Qin Zhou, Wei Liu, Yanming Zhao
Summary: A significant amount of adsorbed gas is present in shale gas reservoirs, making the evaluation and prediction of adsorbed gas crucial for exploration and development. However, the presence of water in shale reservoirs poses challenges. This study systematically reviews the factors controlling water in shale nanopores and its influence on methane adsorption. It reveals that the water content and absorption capacity in shales vary widely and are primarily related to organic matter and mineral compositions. The presence of water reduces methane adsorption capacity to some extent, but even under moist conditions, organic matter in shales still exhibits strong methane adsorption capacity. Clay minerals and nanopore structure directly impact water occurrence and distribution. External factors like pressure and temperature can also influence water distribution and thus the methane adsorption capacity. The paper discusses current issues and highlights future research directions in this field.
Article
Chemistry, Physical
Bo Zhou, Zhendong Zhou, Yang Zhou
Summary: Understanding the transport of gas in shale reservoirs is crucial for estimating reserves and production. This study models nano-scale slits with organic kerogen materials and proposes a solution to quantify mass transfer processes. The results are accurate and consistent with Molecular Dynamics results, validating the model's accuracy for different diffusion mechanisms.
CHEMICAL PHYSICS LETTERS
(2023)
Article
Geochemistry & Geophysics
Yanfeng He, Guodong Qi, Xiangji Dou, Run Duan, Nan Pan, Luyao Guo, Zhengwu Tao
Summary: The study focuses on the adsorption properties of shale oil in organic nanopores. A molecular model is constructed to investigate the adsorption pattern of multicomponent fluids in organic nanopores under different temperature and pore size conditions. The results show that the adsorption quantity of CO2, n-butane, and n-octane in organic nanopores increases with the increase in pore size, while the heat of adsorption is in descending order for CO2, C12H26, C8H18, and C4H10.
Article
Energy & Fuels
Waheed Hammouri, Xiaowen Guo, Mahmoud Abbas, Keqing Wang
Summary: In this study, experiments and analysis were conducted to understand the generation and evolution of nanometer-sized pores in organic-rich shale. It was found that thermal maturity has a significant impact on the formation and development of shale porosity, while the influence of mineral composition and total organic carbon is relatively small. This research provides important guidance for shale gas exploration and development by studying the formation and development of shale porosity and its correlation with thermal maturity.
Article
Energy & Fuels
Jie Chen, Chanjuan Liu, Zhengcai Zhang, Nengyou Wu, Changling Liu, Fulong Ning, Bin Fang, Yizhao Wan, Qingtao Bu, Gaowei Hu
Summary: Strong static electric fields can induce the migration of Na+ and Cl- ions, leading to the decomposition of methane hydrate. Increasing electric field strength enhances the destructive ability of ions to hydrate, resulting in faster decomposition. This study provides insights into a new method for natural gas hydrate extraction and inhibition of hydrate formation in pipelines, as well as the potential of using hydrate as a new ion exchange membrane material in the future.
Article
Thermodynamics
Zhengcai Zhang, Peter G. Kusalik, Nengyou Wu, Changling Liu, Yongchao Zhang
Summary: This study investigates the stability of natural gas hydrates in confined space through molecular simulations, focusing on the effects of pore size and pore surface properties. The results show that the melting points of methane hydrate are controlled by the slit size, while the mineral surface has a minor effect. Additionally, the specific surface area of hydrate particles determines their stability in silica slits. Methane hydrate dissociates faster in confined space, especially in hydrophilic systems.
Article
Chemistry, Physical
Mingmin Zhang, Zhengcai Zhang, Dongdong Ni
Summary: This study investigates the growth mechanism of sH hydrate through large-scale molecular dynamics simulations and finds that the improper trapping of MPD molecules at the hydrate surface is the main cause of slow crystal growth. Increasing pressure promotes hydrate growth, but excessive pressure leads to cross-growth of different types of hydrates. Furthermore, the proper concentration of MPD is also crucial for the growth of sH hydrate.
JOURNAL OF MOLECULAR LIQUIDS
(2022)
Article
Chemistry, Physical
Lei Wang, Kyle Hall, Zhengcai Zhang, Peter G. Kusalik
Summary: This study utilizes molecular simulations to investigate the behavior of CH4/H2S mixed hydrate nucleation. It is found that CH4 is enriched in the hydrate phase while the aqueous phase is enriched in H2S. Nonstandard cages and cages with heptagonal faces play a significant role in the early-stage gas hydrate structural transitions.
JOURNAL OF PHYSICAL CHEMISTRY B
(2022)
Article
Chemistry, Multidisciplinary
Zhengcai Zhang, Peter G. Kusalik, Nengyou Wu, Changling Liu, Fulong Ning
Summary: This study investigated the impacts of calcite nanoparticles on methane hydrate formation through molecular dynamics simulations. The results revealed that the nanoparticles inhibit methane hydrate nucleation and do not have clear connections with nucleated hydrates. Furthermore, the nanoparticles only affect hydrate growth when the growth front approaches the bound water around the nanoparticles.
ACS SUSTAINABLE CHEMISTRY & ENGINEERING
(2022)
Article
Energy & Fuels
Lei Wang, Zhengcai Zhang, Peter G. Kusalik
Summary: This study uses molecular dynamics simulations to investigate the nucleation behavior of gas hydrates in water nanodroplets immersed in a non-aqueous liquid. The study examines key factors influencing nucleation and finds that H2S tends to initiate hydrate formation. The results provide important insights into the molecular mechanism of clathrate hydrate nucleation in water-in-oil emulsions.
Article
Energy & Fuels
Chao Zheng, Guang-Jun Guo, Xuwen Qin, Yanhui Dong, Cheng Lu, Bo Peng, Wei Tang, Hang Bian
Summary: Water/methane two-phase flow in a hydrophilic cylindrical nanopore was studied using molecular simulations, and a water lock model and its formation mechanism were proposed. These findings are valuable for understanding two-phase percolation and optimizing gas production and water removal schemes during hydrate exploitation.
Article
Chemistry, Multidisciplinary
Cuiping Tang, Abdolreza Farhadian, Avni Berisha, Mohamed A. Deyab, Jie Chen, Danial Iravani, Alireza Rahimi, Zhengcai Zhang, Deqing Liang
Summary: Gas hydrate and corrosion inhibitors are commonly used in oil and gas pipelines to ensure smooth flow, but compatibility issues arise when they are co-injected. Using anti-agglomerant hydrate inhibitors is an effective method to control gas hydrate plugging in deep-water hydrocarbon flow lines or drilling operations.
ACS SUSTAINABLE CHEMISTRY & ENGINEERING
(2022)
Article
Chemistry, Multidisciplinary
Yue Zhao, Fansen Zeng, Dachuan Zhao, Lei Lin, Zhengcai Zhang
Summary: This study investigates the growth process of carbon dioxide hydrate in the presence of salt through systematic molecular dynamics simulations. The results show that the growth rate of hydrate decreases with increasing solution salinity, and the number of ions bound in the hydrate structure is related to the growth rate and salinity. The replacement of water molecules by ions at the vertex of the cages is energetically unfavorable. The temperature has a maximum effect on the growth rate, while pressure has a negligible impact. The ion concentration in the hydrate phase decreases with temperature and is hardly affected by pressure. The trapping of ions in the hydrate phase is kinetically controlled by ion diffusion properties.
CRYSTAL GROWTH & DESIGN
(2023)
Article
Energy & Fuels
Jie Chen, Zhengcai Zhang, Yongchao Hao, Daniel Porfirio Luis Jimenez, Jiafang Xu, Nengyou Wu, Fulong Ning, Bin Fang, Jun Zhang, Jianye Sun, Xiluo Hao, Qingguo Meng, YanLong Li, Yizhao Wan, Chanjuan Liu, Gaowei Hu
Summary: The formation and dissociation of gas hydrate can be influenced by electrostatic fields, making it a potential technology with great application value in hydrate exploitation, prevention, and related technologies. The molecular dynamics simulation revealed that the migration and destruction of ions in the hydrate are influenced by the strength of the electrostatic field. The insights gained from this study are beneficial for the application of electrostatic field in hydrate mining and safety of oil and gas pipeline transportation.
Article
Thermodynamics
Zhengcai Zhang, Peter G. Kusalik, Changling Liu, Nengyou Wu
Summary: In this study, molecular simulations were used to investigate the formation of methane hydrates in surface-modified silica pores, and the impact of pore surface characteristics was emphasized. The results showed that methane hydrate formation had no preference towards hydrophobic or hydrophilic pore surfaces. It was also found that pre-filling the pores with methane could accelerate hydrate formation. This study enhances understanding of the hydrate formation process in pores and has implications for the design of gas hydrate promoters or inhibitors.
Review
Geosciences, Multidisciplinary
Yong-chao Zhang, Le-le Liu, Gao-wei Hu, Qing-tao Bu, Cheng-feng Li, Zheng-cai Zhang, Jian-ye Sun, Chang-ling Liu
Summary: This study reviews the formation mechanisms of grain-displacing hydrate from the perspective of geological accumulation and microscale sedimentary property, and proposes shortcomings in current theories and suggestions for future study.
Review
Geosciences, Multidisciplinary
Zheng-cai Zhang, Neng-you Wu, Chang-ling Liu, Xi-luo Hao, Yong-chao Zhang, Kai Gao, Bo Peng, Chao Zheng, Wei Tang, Guang-jun Guo
Summary: This article provides a systematic evaluation of recent advances in molecular dynamics simulation of hydrate nucleation and growth. It explores the enlightening significance of these studies for hydrate applications. Additionally, potential directions for molecular simulation in the research of hydrate nucleation and growth are proposed, and the future of molecular simulation research in this field is discussed.
