Article
Engineering, Environmental
Wenbin Jiang, Gaohui Cao, Chao Luo, Mian Lin, Lili Ji, Ji Zhou
Summary: The study investigated the relationship between the composition of Wufeng-Longmaxi Formation shale samples in Sichuan Basin and methane adsorption characteristics, establishing a composition-based methane adsorption model. Differences in clay contribution to methane adsorption for different sublayers were revealed, aiding in improving the accuracy of shale reservoir evaluation.
CHEMICAL ENGINEERING JOURNAL
(2022)
Article
Energy & Fuels
Zhenhua Tian, Wei Wei, Shangwen Zhou, David A. Wood, Jianchao Cai
Summary: This study conducted a comprehensive analysis of the microstructure characteristics of marine shale samples from the Longmaxi Formation in the Sichuan Basin, China. It identified a complex pore network in these shales, consisting of various pore types such as microfractures, intergranular pores, and organic pores. The research also revealed correlations between total organic carbon content, microstructures, and nanopore distribution.
Article
Energy & Fuels
Liang Huang, Zhengfu Ning, Hao Lin, Wen Zhou, Lu Wang, Jie Zou, Hao Xu
Summary: High-pressure sorption isotherms were measured on shales from Sichuan Basin, China for CH4, C2H6, and their mixtures using a volumetric method. The temperature had a more notable effect on the binary excess sorption isotherms compared to gas composition. C2H6 showed stronger affinity than CH4, with its effect more significant at high pressures and less significant at low pressures.
Article
Energy & Fuels
Shang -Wen Zhou, Dong-Xiao Zhang
Summary: Deep shale gas (3500-4500 m) in China is expected to contribute significantly to the growth of shale gas production. The gas occurrence characteristics of deep shale reservoirs differ from those of shallow and medium layers due to high temperature and high pressure. Methane is mainly adsorbed in the form of micropore filling, while the mesopores store most of the free gas in deep shales. Total organic carbon (TOC) and micropore specific surface area (SSA) are the key factors influencing the adsorption capacity of deep shale. The dominant gas in deep shale gas reservoirs is free gas, with a content ratio of approximately 58%.
Article
Energy & Fuels
Huanquan Sun, Xunyu Cai, Degao Hu, Zhiyong Lu, Peirong Zhao, Aiwei Zheng, Jiqing Li, Haitao Wang
Summary: In the Jiaoshiba block, the employed reserves and recovery factor by primary well pattern are low, and layered development is difficult. The theory and technology of shale gas three-dimensional development are discussed, focusing on fine description and modeling of shale gas reservoir, optimization of three-dimensional development strategy, efficient drilling, precision fracturing, and real-time control. By implementing three-dimensional development, the overall recovery factor in the Jiaoshiba block has increased from 12.6% to 23.3%, providing important support for the continuous and stable production of the Fuling shale gas field.
PETROLEUM EXPLORATION AND DEVELOPMENT
(2023)
Article
Energy & Fuels
Xiang Xu, Lianbo Zeng, He Tian, Kegang Ling, Shiqi Che, Xiao Yu, Zhiguo Shu, Shaoqun Dong
Summary: The characteristics and controlling factors of lamellation fractures in marine shales play a crucial role in the accumulation and preservation of shale gas. Organic matters, brittle minerals, laminae, and pyrite are found to be the main controlling factors affecting the development of lamellation fractures in the Paleozoic Wufeng Formation and Longmaxi Formation in the Fuling Area of Eastern Sichuan Basin.
JOURNAL OF PETROLEUM SCIENCE AND ENGINEERING
(2021)
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
Energy & Fuels
Dai Jinxing, Ni Yunyan, Liu Quanyou, Wu Xiaoqi, Gong Deyu, Hong Feng, Zhang Yanling, Liao Fengrong, Yan Zengmin, Li Hongwei
Summary: The Sichuan Basin is classified as a super gas basin due to its abundant gas source rocks, large remaining recoverable resources, numerous large gas fields, and high total gas production.
PETROLEUM EXPLORATION AND DEVELOPMENT
(2021)
Article
Geochemistry & Geophysics
Chao Qian, Xizhe Li, Weijun Shen, Wei Guo, Yong Hu, Zhongcheng Li
Summary: The study compared the productivity and imbibition characteristics of deep shale gas reservoirs with shallow shale in China, finding that deep shale mainly consists of micropores and mesopores, with a lower imbibition capacity coefficient compared to shallow shale. In addition, saline solutions have an inhibitory effect on shale imbibition.
Article
Geosciences, Multidisciplinary
Ziqi Feng, Fang Hao, Jinqiang Tian, Shangwen Zhou, Dazhong Dong, Shipeng Huang
Summary: This review systematically analyzes the geochemical characteristics of Silurian shale gas in the Sichuan Basin, including its special isotope anomalies. The dominant component of over-mature Longmaxi Formation shale gas is methane, with high CH4 and low C2+ contents. The geochemical anomalies mainly refer to abnormally enriched delta C-13(1) values and full reversal, resulting in deviations in carbon isotope composition and light hydrocarbon data. Understanding the geological processes that led to these anomalies provides valuable insights for studying late-stage gas generation.
EARTH-SCIENCE REVIEWS
(2022)
Article
Geosciences, Multidisciplinary
Zhen Qiu, Jianglin He
Summary: This study investigates the depositional environmental changes and their correlation with organic matter accumulation in the Pliensbachian-Toarcian lacustrine shale in the Sichuan basin. The research found that lake stratification and oxygen deficiency gradually strengthened upward, while primary productivity decreased. The accumulation of organic matter in these lacustrine shales is closely related to tectono-sedimentary evolution and depositional conditions.
JOURNAL OF ASIAN EARTH SCIENCES
(2022)
Article
Energy & Fuels
Fei Zhao, Zaitian Dong, Chaoyong Wang, Wenli Zhang, Rui Yu
Summary: Investigations into the connectivity and complexity of pore systems in shales are essential for understanding the flow of shale gas and the capacities of the associated reservoirs. This study analyzed shale samples from the Wufeng-Longmaxi Formation in the southeast of the Sichuan Basin to examine their microstructural, pore network, and pore connectivity characteristics. The results revealed the presence of micropores, mesopores, and macropores in all shale samples, with micropores and mesopores dominating the total pore volume. The findings also showed that the porosity and specific surface area of pores were higher in samples from the WF Formation compared to the LMX Formation.
Article
Geosciences, Multidisciplinary
Yuxin Hao, Rebecca Bell, Ying Rao, Rui Fan, Yanghua Wang
Summary: By utilizing combined geological and geophysical methods, the characteristics, distribution, and controlling factors of karst reservoirs in the Yuanba gas field of the northern Sichuan Basin were studied. It was found that the seismic attributes, geophysical response, and karst distribution exhibited a strong correlation with paleo geomorphology, fault distribution, and gas contents.
MARINE AND PETROLEUM GEOLOGY
(2023)
Article
Energy & Fuels
Feng Yang, He Zheng, Qiulei Guo, Bin Lyu, Sijia Nie, Huan Wang
Summary: Understanding the penetration and retention of fracturing water in geological systems is crucial for hydrocarbon extraction and fluid disposal during hydraulic fracturing. Water imbibition experiments conducted on shales from the Sichuan Basin in China revealed that water penetration in shales is mainly along the shale lamination and bedding, with developed microfracture networks having higher sorptivity. However, water penetration into shales is usually less than 5 cm, with complex fracture networks and small fracture widths leading to low water recovery.
Article
Geochemistry & Geophysics
Xianglu Tang, Wei Wu, Guanghai Zhong, Zhenxue Jiang, Shijie He, Xiaoxue Liu, Deyu Zhu, Zixin Xue, Yuru Zhou, Jiajing Yang
Summary: The study analyzed the methane adsorption capacity of different types of shales in the Sichuan Basin and found significant differences between marine, transitional, and lacustrine shales. The Longtan Formation exhibited the strongest adsorption capacity, while lacustrine shales had the weakest capacity, primarily influenced by organic matter content and thermal evolution degree.
Article
Geosciences, Multidisciplinary
Jingyi Wang, Fujie Jiang, Qinhong Hu, Chunlin Zhang, Xiaoguang Yang, Wuling Mo, Xirong Wang, Zhenguo Qi
Summary: The central and eastern Paleozoic Carboniferous Benxi Formation in the Ordos Basin, China's largest gas-producing area, poses challenges for exploration due to extreme diagenesis, complex pore structure, and strong heterogeneity. This study conducted qualitative and quantitative analyses to investigate the development and controlling factors of secondary porosity in the formation. The findings provide a basis for predicting favorable reservoirs in the tight sandstones of the Benxi Formation in the Ordos Basin.
MARINE AND PETROLEUM GEOLOGY
(2023)
Article
Geosciences, Multidisciplinary
Jianjiang Wen, Mengdi Sun, Ziang Cui, Jingyi Wang, Heng Zhang, Zhongxian Cai, Mehdi Ostadhassan, Qi Wang, Qinhong Hu
Summary: In this study, the oil charging characteristics and pore structure of the Lower Cambrian Xiaoerbulake Formation in the Tarim Basin were investigated. The results showed that the microbial dolomites had the highest oil charging force and smallest pore throat threshold, making them the most favorable lithofacies for the accumulation and migration of oil and gas.
MARINE AND PETROLEUM GEOLOGY
(2023)
Article
Geosciences, Multidisciplinary
Kefei Chen, Rui Yang, Hanyong Bao, Tian Dong, Aoqi Jia, Qinhong Hu, Xiaowen Guo, Sheng He
Summary: In this study, the influence of paleoenvironmental conditions and diagenetic pathways on pore development of the Wufeng and Longmaxi Formations in shale is investigated. The results show that paleoenvironmental conditions determine the composition and content of minerals and organic matter in shale. Different shale lithofacies undergo various diagenetic events and evolution pathways, which ultimately affect pore generation and evaluation. The content of pores varies in different lithofacies, with siliceous shale containing abundant biogenic authigenic quartz and organic matter, mixed shale having fewer residual pores due to compaction, and clay-rich shale experiencing deformation and loss of primary pores. The amount of organic matter pores gradually decreases from the bottom of the formations to the upper section.
MARINE AND PETROLEUM GEOLOGY
(2023)
Article
Chemistry, Multidisciplinary
Qiming Wang, Qinhong Hu, Chen Zhao, Yang Wang, Tao Zhang, Jan Ilavsky, Mengdi Sun, Linhao Zhang, Yi Shu
Summary: Laboratory-scale analysis of natural rocks provides information about their physical characteristics, such as density, porosity, and pore structure. This study investigated the effect of sample size on the petrophysical properties of different rock samples using various experimental techniques. The results suggest that the sample size influences the pore structure changes during crushing and the fluid-to-pore connectivity.
Article
Engineering, Chemical
Xianglong Fang, Yidong Cai, Qinhong Hu, Ping Gao, Dameng Liu, Yujing Qian
Summary: Exploring the relationship between formation pressure and shale pore evolution is crucial for the development of marine shale gas accumulation theory. Experimental investigations on lowly matured marine shale were carried out to characterize the effects of formation pressure on shale pore morphology and hydrocarbon expulsion. The findings suggest that formation pressure promotes the expulsion of hydrocarbons, changes shale pore morphology, and improves pore connectivity. These results provide valuable insights into understanding the evolution of shale pore structures under different pressure conditions.
Article
Energy & Fuels
Jingchao Luo, Jianping Yan, Majia Zheng, Wei Guo, Guanghai Zhong, Min Wang, Bin Geng, Qinhong Hu
Summary: This study investigates the influence of mineral composition and lamination on the occurrence and mechanical properties of shale in the Luzhou area of the Sichuan Basin. The results show that the quartz content has a positive correlation with Young's modulus, and the laminated layer enhances shale anisotropy and fracture trapping abilities. The study contributes to a better understanding of the rock mechanics and fracture evaluation of shale reservoirs.
Article
Energy & Fuels
Jingyi Wang, Qinhong Hu, Zhongxian Cai, Xiaohui Sun, Mengdi Sun, Cong Zhang, Wei Wei, Ziang Cui
Summary: A study on 12 lacustrine shale samples from Lucaogou Formation reveals that the mineral compositions and organic matter abundance influence the pore system development and retained oil distribution. The samples are dominated by mineral-related slit-shaped pores with a small amount of organic matter-hosted pores. Feldspar dissolution leads to abundant dissolved pores, improving reservoir properties. Quartz overgrowth negatively affects pore structure, while carbonates undergo dissolution and cementation processes. Mineral sizes are positively related to pore diameter, and source-proximal sedimentary microfacies with coarse components are more favorable for oil exploration. Retained oil primarily occurs as a thin film in pores with diameters of 100-1500 nm, while oil in smaller pores is adsorbed. The retained oil volume is affected by organic matter abundance, storage type, and material source-reservoir configurations.
Article
Geosciences, Multidisciplinary
Mengdi Sun, Xianggang Duan, Qing Liu, Tomasz P. Blach, Mehdi Ostadhassan, Bo Liu, Yeping Ji, Qinhong Hu, Zhejun Pan
Summary: This study investigates the pore-fracture connectivity in overmature marine shale samples using small-angle neutron scattering (SANS), repeated mercury intrusion capillary pressure (MICP), and field emission scanning electron microscopy (FE-SEM) imaging. The results show that sealing of the pore system by brittle minerals reduces overall pore connectivity within the shale matrix. The combination of MICP measurements and FE-SEM imaging provides a new evaluation method for pore-fracture connectivity. The study also reveals that a small fraction of pores in overmature shales are accessible to methane, and under high pressure, the density of methane in small pore spaces is greater than that of an ideal gas and forms nanoscale methane clusters.
MARINE AND PETROLEUM GEOLOGY
(2023)
Article
Geosciences, Multidisciplinary
Longhui Bai, Bo Liu, Xiaofei Fu, Qinhong Hu, Qiuli Huo, Liu Wang, Qiming Wang, Li Fu, Mehdi Ostadhassan
Summary: An accurate assessment of shale oil mobility is essential for cost-effective exploitation. This study presents a method to evaluate shale oil mobility by integrating pore structure and oil states distributions. The relationships between organic extracts and oil states were determined, and the T2-cutoff values were used to indicate the pore size ranges of different oil states. The findings can be used as a reference for evaluating shale oil potential and prospectivity in other regions.
GEOSCIENCE FRONTIERS
(2023)
Article
Energy & Fuels
Binqian Yin, Qinhong Hu, Yingying Zhu, Keren Zhou
Summary: In analyzing geological processes, segmenting SEM images of geological samples is crucial but time-consuming. To automate the segmentation, supervised learning approaches have been used, but they require expensive and error-prone label preparation. In this work, we investigated unsupervised and semisupervised approaches for fine-grained shale and developed a semi-supervised learning model, SU-Net, which demonstrated higher accuracy and faster training than existing models.
GEOENERGY SCIENCE AND ENGINEERING
(2023)
Article
Energy & Fuels
Shuling Xiong, Manfei Chen, Hui Yu, Weihang Zhang, Qinhong Hu, Sheng He, Rui Yang
Summary: This study investigates the adsorption behavior and mechanisms of water vapor and nitrogen on four typical clay minerals. The results show that pores with a diameter smaller than 10 nm contribute significantly to water uptake. The FHH model is the most optimal for describing and predicting water vapor adsorption isotherms on the clay minerals. The findings provide important insights for determining water distribution in shale reservoirs and evaluating shale gas content.
GAS SCIENCE AND ENGINEERING
(2023)
Article
Energy & Fuels
Qinhong Hu, Qiming Wang, Tao Zhang, Chen Zhao, Khawaja Hasnain Iltaf, Shiqi Liu, Yuta Fukatsu
Summary: This study evaluates the petrophysical properties of representative geological rocks for the effective utilization and long-term storage of carbon dioxide. Laboratory tests were performed on various rock samples, showing a disparity in properties between rocks selected for CO2 storage and potential caprocks. The understanding of pore structure and fracture contribution is critical for reliable CO2 storage and utilization. The study also highlights the controlling influence of grain size distribution and geological processes on pore attributes for different rock types.
Article
Energy & Fuels
Yang Wang, Hong-Fei Cheng, Qin-Hong Hu, Lang-Bo Jia, Xi-Meng Wang, Sha-Sha Gao, Luo-Fu Liu
Summary: The excess adsorption of methane under supercritical conditions was studied in two mudstone samples from the Yanchang Formation, Ordos Basin. The supercritical Dubinin-Radushkevich (SDR) model was determined to be the most accurate model for fitting the measured excess adsorption. The adsorption of methane on mudstone is a physisorption process controlled by the heterogeneity and interaction forces between the methane molecule and the rock surface.
Article
Energy & Fuels
Xiaoming Zhang, Ren Wang, Wanzhong Shi, Qinhong Hu, Xiaofeng Xu, Zhiguo Shu, Yang Yang, Qian Feng
Summary: Descriptions, field emission-scanning electron microscopy and geochemical analyses were used to study the developmental properties and controlling factors of natural fractures in the Wufeng-Longmaxi Shales. The study revealed the presence of non-tectonic bedding fractures, tectonic fractures, and micro-fractures. The extent of fracture development is influenced by external structural and internal lithofacies factors. The research provides a model for the development of natural fractures and their impact on shale gas accumulation.
GEOENERGY SCIENCE AND ENGINEERING
(2023)
Article
Geosciences, Multidisciplinary
Weihang Zhang, Rui Yang, Zhiliang He, Hanyong Bao, Hui Yu, Shuling Xiong, Yuanjia Han, Qinhong Hu, Sheng He
Summary: This study investigates the influence of mineral composition, pore structure, and extractable organic components on the wettability of shale. The results demonstrate that shale with different lithofacies have different wettability characteristics, and minerals and pore types play a significant role in wettability alteration.
MARINE AND PETROLEUM GEOLOGY
(2023)
