Article
Geosciences, Multidisciplinary
Kun Zhang, Zhenxue Jiang, Yan Song, Chengzao Jia, Xuejiao Yuan, Xueying Wang, Liwen Zhang, Fengli Han, Yiming Yang, Yao Zeng, Pei Liu, Liangyi Tang, Xuecheng Chen, Zehao Zheng
Summary: This study focuses on the analysis of major hydrocarbon-bearing basins in China that are rich in shale with terrestrial facies, with a particular emphasis on the Jurassic Lianggaoshan Formation in the Southeast Sichuan Basin. The study investigates the pore connectivity, pore wettability, and shale oil mobility of different shale lithofacies using various analytical techniques. The results show that organic-rich clay shale and mixed shale have good pore connectivity, while organic matter-bearing clay shale has moderate connectivity. The wettability and mobile oil saturation also vary among different lithofacies.
FRONTIERS IN EARTH SCIENCE
(2022)
Article
Energy & Fuels
He Zheng, Feng Yang, Qiulei Guo, Songqi Pan, Shu Jiang, Huan Wang
Summary: The accurate evaluation of microscopic pore structure characteristics of shales is crucial for shale oil development. In this study, various methods were used to investigate the pore structure of silty shale samples from the Upper Triassic Yanchang formation in Ordos Basin. The results revealed the development of five typical pores and the range of pore sizes in the samples. The combination of different methods provided reasonably consistent results, aiding in the understanding of storage space and transport property of lacustrine shale oil.
JOURNAL OF PETROLEUM SCIENCE AND ENGINEERING
(2022)
Article
Energy & Fuels
Dong Hui, Yan Zhang, Yong Hu, Xian Peng, Longxin Li, Zihan Zhao, Xixiang Liu, Tao Li, Yi Pan
Summary: Knowledge of shale pore structure is crucial to understand gas storage and seepage mechanisms. The study investigated the spatial distribution and connectivity of organic matter (OM) pores in shale samples using scanning electron microscopy. The findings showed that the type of OM controlled the development of organic pores, with honeycomb-shaped, spongy-shaped, and slit-like irregular pores mainly formed in pyrobitumen. The pore size distribution of honeycomb-shaped OM pores was mainly in the range of 10-50 and 80-100 nm. The permeability simulation revealed discrepancies in different directions due to the heterogeneity of the OM pores.
ENERGY SCIENCE & ENGINEERING
(2023)
Article
Geosciences, Multidisciplinary
Kun Zhang, Shu Jiang, Rui Zhao, Pengfei Wang, Chengzao Jia, Yan Song
Summary: This study provides a comprehensive depiction of the 3D connectivity of organic matter (OM) pores in shale. The results indicate that the connectivity of shale is mainly contributed by the well-distributed and structurally advantageous OM pores, which can significantly improve gas adsorption and percolation in the shale reservoir.
GEOLOGICAL JOURNAL
(2022)
Article
Energy & Fuels
Tomasz Blach, Andrzej P. Radlinski, Phung Vu, Yeping Ji, Liliana de Campo, Elliot P. Gilbert, Klaus Regenauer-Lieb, Maria Mastalerz
Summary: The study found that different pore sizes are affected differently by uniaxial stress, with mesopores around 100 nm being the most affected. Additionally, it was discovered that high pressure can increase the number density of large macropores, promoting gas migration and improving recovery rates. After pressure cycling, an irreversible rearrangement of pore size distribution takes place.
INTERNATIONAL JOURNAL OF COAL GEOLOGY
(2021)
Article
Multidisciplinary Sciences
Xuan Lin, Yongqiang Bai, Yan Zhang, Xiuli Lu, Shenghao Song, Jiyu Jiang, Cuiting Zhang
Summary: The shape of quartz pores significantly impacts the adsorption state of methane. In this study, wedge-shaped triangular quartz pores were created to investigate the occurrence states of methane. Molecular dynamic simulations were conducted at a temperature of 323 K and a pressure of 30 MPa. The results show that the adsorption state of methane is influenced by the wedge angle, with increased density and number of adsorption layers as the wedge angle increases. The interaction between methane and quartz, as well as the energy state of each methane molecule, determine the state of methane in the pore.
ARABIAN JOURNAL FOR SCIENCE AND ENGINEERING
(2023)
Article
Engineering, Chemical
Chuxiong Li, Baojian Shen, Longfei Lu, Anyang Pan, Zhiming Li, Qingmin Zhu, Zhongliang Sun
Summary: This study quantitatively characterizes the pores and microfractures of marine shale samples from the Longmaxi Formation in the southeastern Sichuan Basin using NMR T-2 spectra analysis. The results show that organic pores are the dominant type of pores, and NMR porosity includes closed pores and microfractures.
Article
Geosciences, Multidisciplinary
Lingjie Yu, Keyu Liu, Ming Fan, Zhejun Pan
Summary: The study found significant differences in pore connectivity among different types of shales, with mixed mudstone showing excellent connectivity, siliceous shale presenting overall poor connectivity, and argillaceous shale primarily non-interconnected.
FRONTIERS IN EARTH SCIENCE
(2021)
Article
Geochemistry & Geophysics
Yuqi Wang, Dongxia Chen, Yuchao Wang, Wenzhi Lei, Fuwei Wang
Summary: This study analyzed the types and characteristics of shale lithofacies in the Lower Cambrian Qiongzhusi Formation in the Sichuan Basin. It found significant differences in pore structure among different lithofacies, with S-3 shale having the most abundant pores. Clay mineral content was identified as the main factor affecting shale pore structure.
Article
Thermodynamics
Jianguang Wei, Jiangtao Li, Ao Zhang, Demiao Shang, Xiaofeng Zhou, Yintao Niu
Summary: This paper examines the development characteristics of shale pores and fractures, revealing that the pore space varies widely in size, primarily in the nanoscale range, and the proportion of organic pore area is much higher than that of mineral pore area. The study also finds that shale porosity has strong heterogeneity, with minerals and maturity playing important roles in throat diameter, geological compaction and tectonism affecting the tortuosity of shale reservoir pores, and pore connectivity primarily influencing shale wettability.
Article
Energy & Fuels
Debin Xia, Zhengming Yang, Tiening Gao, Haibo Li, Wei Lin
Summary: This study used high-precision high-pressure mercury intrusion experimental techniques and fractal theory to analyze the micro-nano-pore structure characteristics and heterogeneity of shale oil reservoirs. The research found that the micro-nano-pores in the shale oil reservoir are concentrated and continuous, distributed in the range of 30-500 nm, with a larger fractal dimension indicating stronger heterogeneity.
JOURNAL OF PETROLEUM EXPLORATION AND PRODUCTION TECHNOLOGY
(2021)
Article
Geosciences, Multidisciplinary
Zhixing Yi, Shouzhi Hu, Songtao Wu, Jingsheng Ma, Jian Gao, Yahui Yuan
Summary: Most pore network models designed for sandstone may not be applicable for shale due to the presence of nanopores and non-Darcy effects. A new pore network model accounting for these effects was proposed, providing a more accurate solution for shale gas flow simulations. Experiments on a shale sample showed differences in network structures between the new model (APN) and traditional models (IPN).
MARINE AND PETROLEUM GEOLOGY
(2021)
Article
Chemistry, Physical
Ziqiang Wang, Hongkui Ge, Wei Zhou, Yun Wei, Bei Wang, Sai Liu, Hao Zhou, Shuheng Du
Summary: This study used data-driven evaluation to investigate the internal control factors of pores and microfractures in tight conglomerate reservoirs. The results showed that microfractures dominate in fluid storage and seepage, while pores are more conducive to a homogeneous distribution of seepage flow and improved sweep efficiency.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2022)
Article
Thermodynamics
Jianguo Wu, Chao Luo, Kesu Zhong, Yi Li, Guoliang Li, Zhongming Du, Jijin Yang
Summary: To accurately and comprehensively analyze the properties of organic nanopores in marine shale, an integration method using helium ion microscope (HIM), scanning electron microscope (SEM), focused ion beam-HIM (FIB-HIM), and FIB-SEM was proposed. Results showed that organic pores below 10 nm significantly impact shale gas storage and productivity evaluation by affecting porosity, surface area, pore size distribution, and connectivity characteristics. The integration method revealed an increase in surface porosity by 10.73% and an increase in specific surface area by 76%. It also showed that the formation of organic nanopores occurs in multiple stages, with larger bubble pores appearing during oil generation and smaller spongy pores appearing during gas generation. The organic pores revealed by FIB-HIM exhibited higher coordination numbers and a higher proportion of inner-connected volume, indicating more complex connectivity characteristics. Despite limitations, these novel insights highlight the importance of exploring organic nanopores at the nanoscale and have the potential to inform further research in this field.
Article
Chemistry, Physical
Shiyu Xu, Mahmood Reza Yassin, Hassan Dehghanpour, Christen Kolbeck
Summary: This study investigates the hydrocarbon potential of calcareous shale plugs by examining their wettability and pore structure. The results show that plugs with low maturity level in the early-oil window have low oil potentials despite their TOC-rich characteristics.
JOURNAL OF MOLECULAR LIQUIDS
(2022)
Article
Energy & Fuels
Guanqun Li, Yuliang Su, Wendong Wang, Qinghao Sun
Summary: This study investigates the mechanism of forced imbibition in energized hydraulic fracturing technology and establishes mathematical models. The research finds that forced imbibition is faster than spontaneous imbibition and leads to higher oil recovery, with smaller pores playing a significant role in the imbibition rate.
Article
Energy & Fuels
Zongfa Li, Yuliang Su, Lei Li, Yongmao Hao, Wendong Wang, Yang Meng, An Zhao
Summary: This study explored the potential of water alternating gas (WAG) flooding in CO2 storage through experimental and numerical simulation methods. It was found that WAG flooding after water flooding enhanced oil recovery, but also displaced some of the previously stored CO2. The study identified key factors influencing CO2 storage and achieved higher CO2 storage through optimization.
Article
Water Resources
Han Wang, Yuliang Su, Wendong Wang
Summary: Understanding the mechanisms of nanoconfined liquid flow in nanoporous media is crucial for various applications. This study summarizes and establishes four theoretical models for liquid flow in nanopores and indicates that the apparent viscosity model is the most suitable for coupling lattice Boltzmann method (LBM). A local-apparent-viscosity LBM (LAV-LBM) is proposed to simulate liquid flow in nanoporous media, considering slip boundary and heterogeneous viscosity/density effects. The effects of molecular interactions, porous media geometry, and wall wettability on apparent permeability are discussed using LAV-LBM simulations.
ADVANCES IN WATER RESOURCES
(2022)
Article
Energy & Fuels
Lipeng Zhang, Tianxiang Wang, Ibrahim Albouzedy, Wendong Wang, Xiang Ren
Summary: This paper analyzes the effects of inter-well interference on productivity by studying field data, using three infill horizontal wells in the Sulige East II area gas field as examples. It provides guidance for optimizing fracturing design.
NATURAL GAS INDUSTRY B
(2022)
Article
Chemistry, Physical
Jun Zhang, Qi Wei, Bojin Zhu, Wendong Wang, Lei Li, Yuliang Su, Peng Wang, Youguo Yan, Jiawei Li, Zhen Li
Summary: The colloidal structure and interactions of crude oil in pipelines were studied using large-scale dissipative particle dynamics simulations and all-atom molecular dynamics simulations. The results showed that temperature, pressure, and flow speed collectively influenced the colloidal structure of crude oil, and the competitive adsorption of crude oil components on pipeline surface was revealed.
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
(2022)
Article
Mathematics, Interdisciplinary Applications
Guanqun LI, Yuliang Su, Wendong Wang
Summary: Large-scale hydraulic fracturing is crucial for efficient shale oil production, but the mechanisms of fracturing fluid flow in shale micropores and the impact of shale microstructure and physical properties are not well understood. This lack of understanding hinders the optimization of fracturing flowback and limits shale oil recovery enhancement. This study analyzes the characteristics of shale pores using SEM and XRD experiments, finding multiple pore types including organic pores, brittle mineral pores, and clay pores. The study investigates the influence of cross-section shapes on capillary force and analyzes the dynamics of imbibition in different pore types. A shale semi-analytical solution that considers imbibition time, fluid properties, pore cross-section shapes, tortuosity, and forced pressure is established using a shale multi-pores physical model and fractal theory.
FRACTALS-COMPLEX GEOMETRY PATTERNS AND SCALING IN NATURE AND SOCIETY
(2023)
Article
Energy & Fuels
Yuxuan Deng, Wendong Wang, Yuliang Su, Shibo Sun, Xinyu Zhuang
Summary: In this study, a double sweet spot analysis system and an optimization method for sweet spot parameters were proposed. Unsupervised machine learning algorithms were used to determine the classification standard of general reservoirs and high-quality sweet spot reservoirs. The results show that this method can accurately locate the sweet spot in gas fields.
JOURNAL OF ENERGY RESOURCES TECHNOLOGY-TRANSACTIONS OF THE ASME
(2023)
Article
Energy & Fuels
Zongfa Li, Yuliang Su, Fuxiao Shen, Lijuan Huang, Shaoran Ren, Yongmao Hao, Wendong Wang, Yang Meng, Yang Fan
Summary: The feasibility of N2 alternating CO2 injection for improving CO2 storage and oil production was investigated through laboratory experiments and numerical simulation. The results showed that the N2 alternating CO2 flooding had 2.1% lower CO2 storage factor and 7.1% lower enhanced oil recovery compared to continuous CO2 injection. However, the larger the N2 slug volume, the lower the EOR and CO2 storage factor, due to the reduction of CO2 concentration in the gas phase and CO2 solubility in oil and water. Nevertheless, the N2 slugs significantly reduced mobility differences between flowing zones, resulting in a 1.78 times larger gas swept area and a 44% higher cumulative oil production compared to continuous CO2 injection. Moreover, the optimized N2 alternating CO2 injection scheme achieved 19.6% more CO2 storage than continuous CO2 flooding at a field scale. This study provides valuable experimental and theoretical support for improving CO2 storage and oil production in an oil reservoir.
Article
Energy & Fuels
Wendong Wang, Chengwei Wang, Yuliang Su, Yang Zhao, Jiayi Wen, Lei Li, Yongmao Hao
Summary: CO2 storage is an important technique for achieving carbon peak and carbon neutralization, and depleted gas reservoirs are potential candidates for geological CO2 storage. High water-bearing wells in volcanic depleted gas reservoirs can be selected for CO2 storage. The gas-water distribution characteristics of the gas reservoir after CO2 injection are evaluated and the CO2 injection timing and volume are optimized. Typical wells have been selected for CO2 storage based on the research results.
Article
Energy & Fuels
Wendong Wang, Xincheng Guo, Penghui Duan, Bo Kang, Da Zheng, Atif Zafar
Summary: This study simulated the plugging process by microspheres and nanospheres and evaluated their plugging performance on the core matrix. The best combination of injection parameters was optimized and the results showed that nanospheres had a higher plugging rate compared to microspheres. The maximum oil recovery after plugging was achieved with an injection ratio of 2:1 between nanospheres and microspheres, a total injection of 0.6 pore volume, an injection rate of 1.5 mL/min, and an aging time of 6 days.
NATURAL GAS INDUSTRY B
(2023)
Article
Energy & Fuels
Wendong Wang, Jiayi Wen, Chengwei Wang, Sina Rezaei Gomari, Xinyue Xu, Shuang Zheng, Yuliang Su, Lei Li, Yongmao Hao, Dongxia Li
Summary: CO2 storage with enhanced gas recovery (CSEGR) technology is a pivotal solution for mitigating the greenhouse effect and complying with energy conservation and emission reduction policies. This paper thoroughly analyzes the mechanisms and potential of CO2 storage in gas reservoirs, as well as the factors affecting CSEGR. It also examines the current challenges and future trends in CSEGR development.
Article
Chemistry, Multidisciplinary
Han Wang, Jianchao Cai, Yuliang Su, Zhehui Jin, Mingshan Zhang, Wendong Wang, Guanqun Li
Summary: In this study, an improved multicomponent and multiphase lattice Boltzmann method is proposed to investigate the effects of water phase on CO2 huff-n-puff in shale nanoporous media. The competitive adsorption behaviors between oil and CO2 and the miscibility of oil-CO2 are considered. Additionally, the effects of oil-CO2 miscibility on oil-water flow behaviors and relative permeability are discussed. The results show that water phase has a significant impact on oil recovery and CO2 storage, and the oil-CO2 miscibility affects the oil-water relative permeability in calcite nanoporous media.
Editorial Material
Engineering, Chemical
Wei Yu, Zhiming Chen, Bin Wang, Wendong Wang, Kamy Sepehrnoori
TRANSPORT IN POROUS MEDIA
(2023)
Article
Energy & Fuels
Qiuheng Xie, Wendong Wang, Yuliang Su, Han Wang, Zhouyuan Zhang, Wubin Yan
Summary: In this study, a pore-scale numerical simulation based on the lattice Boltzmann method is used to investigate the calcite dissolution process. The impact of pressure difference and temperature on the dissolution dynamics and dissolution patterns are analyzed. The results show that pressure difference has a decreasing effect on calcite dissolution with increasing temperature, and high temperature and high injection rate are favorable for mineral trapping.
GAS SCIENCE AND ENGINEERING
(2023)
Article
Energy & Fuels
Zhong-Zheng Wang, Kai Zhang, Guo-Dong Chen, Jin-Ding Zhang, Wen-Dong Wang, Hao-Chen Wang, Li -Ming Zhang, Xia Yan, Jun Yao
Summary: Production optimization is crucial in the smart oilfield community for maximizing economic benefits and oil recovery. This study proposes an efficient and robust method, evolutionary-assisted reinforcement learning (EARL), to achieve real-time production optimization under uncertainty. The approach models the optimization problem as a Markov decision process and uses a deep convolutional neural network to adaptively adjust well controls based on reservoir states. Simulation results demonstrate that EARL outperforms prior methods in terms of optimization efficiency, robustness, and real-time decision-making capability.