Article
Energy & Fuels
Jian Xiong, Yukang Li, Shangwen Zhou, Xiangjun Liu, Hui Han, Lixi Liang, Jun Zhao
Summary: In this study, the pore structure characteristics of shales and the factors controlling them were analyzed using various methods. The results showed that the main minerals in the shales are quartz and clay minerals, and the organic matter and quartz have a positive influence on the pore structure parameters, while clay minerals have a negative impact. The pore volume and specific surface area of the shales vary within a certain range, with mesopores and macropores contributing the most to the total pore volume and mesopores contributing the main specific surface area.
JOURNAL OF PETROLEUM EXPLORATION AND PRODUCTION TECHNOLOGY
(2022)
Article
Geosciences, Multidisciplinary
Xueyuan Li, Shangbin Chen, Yiwen Wang, Yingkun Zhang, Yang Wang, Jianfa Wu, Junjian Zhang, Jamil Khan
Summary: The pore structure and pore water in deep shale gas reservoirs are unique and have a significant impact on gas occurrence. The development of pores by organic matter controls the connectivity of deep shale. Different burial depths and beds result in significant differences in pore structure, and mineral anti-compaction protection pores and reservoir fluid over-pressure are crucial for the development of organic pores. Primary formation water plays a vital role in the occurrence and enrichment of shale gas.
NATURAL RESOURCES RESEARCH
(2022)
Article
Energy & Fuels
Min Li, Xiongqi Pang, Liang Xiong, Tao Hu, Di Chen, Zhen Zhao, Shasha Hui, Yang Liu, Siyu Zhang
Summary: The study systematically analyzed the shale gas occurrence characteristics of deep high-over mature shales using the Longmaxi Formation as an example, and found that factors such as temperature, pressure, pore structure, and organic matter content have an influence on the occurrence characteristics of shale gas.
Article
Geosciences, Multidisciplinary
Zisang Huang, Zhongquan Li, Wenrui Shi, Xiyan Yang, Xingzhi Wang, Steven Young
Summary: This study reconstructs the sedimentary mechanisms of shale in the southern Sichuan Basin by combining logging, mineralogy, and geochemistry. The study found that the shale in the area can be divided into different sequences, which are influenced by factors such as volcanic eruption and glaciation, leading to different sedimentary environments and lithofacies. This has significant implications for the development and exploration of shale gas.
MARINE AND PETROLEUM GEOLOGY
(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
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
Energy & Fuels
Jianchao Cai, Zhenhua Tian, Shangwen Zhou, Yihua Xiong, Chenhao Sun, Jianhui Zeng
Summary: This study focuses on the quantitative characterization of fluid storage and structural properties of deep Longmaxi Formation shale samples from southern Sichuan Basin. Experiments including nuclear magnetic resonance and nitrogen adsorption are conducted to analyze pore distribution complexity and pore surface irregularity, which are controlled by factors such as stratigraphic division and shale composition. The research findings suggest that the storage capacity and microstructural properties of deep shales are influenced by stratigraphic division and shale composition.
Article
Geosciences, Multidisciplinary
Shun He, Qirong Qin, Hu Li, Shengxian Zhao
Summary: This study investigates the geological characteristics and exploration potential of shale gas in the southern Sichuan Basin. The research focuses on the coupling relationship between hydrocarbon generation and storage conditions of the Longmaxi Formation, as well as the preservation conditions from the lateral and vertical migration mechanisms of shale gas. The results show that the organic-rich shale at the bottom was formed in a strongly euxinic and anoxic reducing environment. The organic matter type in the shale is dominantly type I kerogen and a small amount of type II1 kerogen. The enrichment of siliceous organisms increases the organic matter and enhances the brittleness of shale, resulting in superior hydrocarbons and a favorable reservoir. The high vertical formation pressure guarantees the sealing of shale and restrains the lateral and vertical escape of shale gas. The analysis of three-dimensional preservation conditions suggests that areas with a short tectonic uplift time, small amplitudes, large-scale underdeveloped fractures, and a high formation pressure coefficient are favorable for shale gas exploration.
FRONTIERS IN EARTH SCIENCE
(2022)
Article
Geosciences, Multidisciplinary
Chao Han, Yuetong Zhang, Guorui Wang, Hua Li, Zhihui Zhang, Qiang Li
Summary: Accurate investigation of shale pores is critical to the assessment of shale-gas reservoir properties. In this study, qualitative and quantitative methods were used to study the pores in black shale from the Southern Sichuan Basin. The results showed the composition and properties of the black shale, as well as the characteristics and distribution of different types of pores. The accuracy of the results was affected by the determination of segmentation thresholds in CT and transverse surface relaxivity in NMR.
FRONTIERS IN EARTH SCIENCE
(2022)
Article
Geochemistry & Geophysics
Xin Wang, Jianhui Zeng, Jinhui Chen, Zhenxue Jiang, Zixin Xue, Xiangye Kong, Qianyou Wang, Kunkun Jia
Summary: This paper investigates the relationship between gas content and micro storage and sealing capacities in deep shale reservoirs. By collecting and summarizing data and using various experimental methods, the influence of factors such as graphitization degree and water saturation on gas content in deep shale reservoirs is analyzed. The research findings serve as a reference for further identifying patterns for high-yield and rich shale gas reservoirs and improving deep shale gas exploration technologies.
Article
Geosciences, Multidisciplinary
Xueyuan Li, Shangbin Chen, Jianfa Wu, Jian Zhang, Shengxian Zhao, Ziqiang Xia, Yang Wang, Shaojie Zhang, Junjian Zhang
Summary: This study quantitatively evaluates the pore water of deep shale gas reservoirs using a combination of NMR technology and theoretical models. The results show that pore water mainly exists in an adsorbed phase with an average adsorption ratio of 69.26% and an average adsorption thickness of 0.5392 nm. Adsorbed and free water coexist in pores of 3-100 nm, with equivalent content and saturation in pores of 10 nm and 6-7 nm, respectively. This study offers a novel approach for characterizing the occurrence and transport of pore water.
MARINE AND PETROLEUM GEOLOGY
(2023)
Article
Geochemistry & Geophysics
Hongzhi Yang, Xuewen Shi, Chao Luo, Wei Wu, Yi Li, Yifan He, Kesu Zhong, Jianguo Wu
Summary: This study analyzed the mineral composition of WF-LF shale in Luzhou using field emission scanning electron microscope and Advanced Mineral Identification and Characterization System. Quartz was identified as the dominant mineral, while siliceous and carbonaceous minerals were found to have a positive effect on reservoir compressibility. Four types of reservoirs were identified based on mineralogical features.
Article
Geochemistry & Geophysics
Hongzhi Yang, Shengxian Zhao, Bo Li, Yong Liu, Majia Zheng, Jian Zhang, Yongyang Liu, Gaoxiang Wang, Meixuan Yin, Lieyan Cao
Summary: The microscopic pore throat structure of shale reservoir rocks directly affects the reservoir seepage capacity. This study focuses on the marine shale from the Upper Silurian to Lower Ordovician Wufeng-Longmaxi Formation in the southern Sichuan Basin to clarify the microstructural characteristics and influencing factors of deep organic-rich shales. Various techniques were used to quantitatively and qualitatively characterize the mineral composition and pore structure. The results provide strong support for the development of deep shale gas in the southern Sichuan Basin.
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
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)