Article
Energy & Fuels
Wen Liu, Qiuchen Xu, Haizhou Wang, Peng Liu, Ruiliang Guo, Yang Zhang, Keyi Wei
Summary: The study found that inorganic pores are the main component of pore space in transitional shale from the North China Basin, with micropores having a greater impact on CH4 adsorption capacity. Clay minerals were identified as the primary factor influencing methane adsorption capacity in this study.
JOURNAL OF PETROLEUM EXPLORATION AND PRODUCTION TECHNOLOGY
(2022)
Article
Geosciences, Multidisciplinary
Yifan Gu, Xingtao Li, Lin Qi, Shuxin Li, Yuqiang Jiang, Yonghong Fu, Xiaoshuai Yang
Summary: In this study, the Shanxi Formation Shan 2(3) Submember transitional shale in the Eastern Ordos Basin was investigated using petrographic, mineralogical, and high-resolution geochemical analyses. The results revealed the sedimentary environment, detrital influx, paleoclimate, paleosalinity, and paleoredox conditions of the submember. The submember was found to be divided into four sections with different facies and characteristics, including bay facies with high TOC values, low detrital influx, and relatively anoxic reduction conditions, and transitional facies dominated by barrier island, lagoon, tidal flat, and swamp.
FRONTIERS IN EARTH SCIENCE
(2022)
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
Energy & Fuels
Juan Teng, Hucheng Deng, Yu Xia, Wenling Chen, Meiyan Fu
Summary: Organic matter composition plays a crucial role in determining the hydrocarbon generation potential of black shales, with significant differences observed in AOM type and content between shales from different regions.
Article
Energy & Fuels
Xiaoguang Yang, ShaobinGuo
Summary: Transitional shale gas, rich in type III organic matter and having obvious lamellation, presents a different sedimentary environment and reservoir characteristics compared to marine shale. Studying the preservation capacity is crucial for understanding whether natural gas formed in these shales would be lost. Research in the Southern North China Basin has shown high macropore proportions and TOC content in transitional shale, indicating the need for further investigation on preservation capacity.
JOURNAL OF NATURAL GAS SCIENCE AND ENGINEERING
(2021)
Article
Energy & Fuels
Ende Deng, Qian Zhang, Zhijun Jin, Rukai Zhu, Zhihua Yan, Bingren Jiang, Ralf Littke
Summary: “This study presents the organic and inorganic geochemical characterization of the Permian Longtan Shale in Guizhou Province, China. The results suggest that the Longtan Shale has high hydrocarbon generation potential, making it suitable for shale gas exploration.”
INTERNATIONAL JOURNAL OF COAL GEOLOGY
(2022)
Article
Energy & Fuels
Xinhua Ma, Hongyan Wang, Qun Zhao, Yong Liu, Shangwen Zhou, Zhiming Hu, Yufeng Xiao
Summary: Under the guidance of extreme utilization theory, this article proposes a basic idea and solutions for efficient development of deep shale gas and applies them in practice. By establishing transparent geological body, optimizing drilling and completion processes, and implementing efficient management, the extreme utilization development of shale gas is achieved.
PETROLEUM EXPLORATION AND DEVELOPMENT
(2022)
Article
Geosciences, Multidisciplinary
Wenping Liu, Juan Wu, Hua Jiang, Zheng Zhou, Chao Luo, Wei Wu, Xiaojia Li, Shugen Liu, Bin Deng
Summary: This study examines the relationship and multi-stage evolution between the upper Ordovician Wufeng and lower Silurian Longmaxi formations at the Changning shale gas field in southern Sichuan basin. The research utilizes low-temperature thermochronological data and structural evolution to analyze the rapid exhumation and history of the field. The results suggest a four-stage thermal evolution and significant impact of pressure index changes on shale gas enrichment.
MARINE AND PETROLEUM GEOLOGY
(2021)
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
Geosciences, Multidisciplinary
Changan Shan, Congchen Ye, Zhao Zhang, Chen Zou, Fangyu He, Hanbing Zhang, Jue Mei, Kaigui Yin, Yakun Shi, Boshuo Li, Fengqi Zhang, Yifan Diao
Summary: This article analyzes the geological characteristics, sedimentary environment, and reservoir characteristics of transitional shale gas in the southern Sichuan basin. The results show that the region has favorable conditions for shale gas accumulation, making it a potential key area for future exploration and development.
FRONTIERS IN EARTH SCIENCE
(2022)
Article
Geosciences, Multidisciplinary
Hui Xiao, Nan Xie, Yuanyuan Lu, Tianyue Cheng, Wei Dang
Summary: The study of the pore structure and its controlling factors in shale reservoirs is crucial for the exploration and exploitation of shale gas. This study focused on the effects of organic and inorganic compositions on the pore structure development of Shanxi shale in the Ordos Basin. The results showed that the mineral composition and organic matter type are key factors in determining the pore structure of shale. The pore structure plays a significant role in the characteristics and development potential of shale.
FRONTIERS IN EARTH SCIENCE
(2022)
Article
Geosciences, Multidisciplinary
Jianwei Lv, Songhang Zhang, Ning Yang, Chunbo Fu, Xinlu Yan, Yang Li
Summary: The study reveals the paleoenvironmental controls on organic matter accumulation in the Upper Paleozoic shales of the eastern Ordos Basin in China, indicating a persistent process of chemical weathering and transitional sedimentation in a continental margin setting. The characteristics of rare earth elements and redox environmental indices suggest a felsic origin for the shales, without the influence of seawater or hydrothermal fluids during deposition.
FRONTIERS OF EARTH SCIENCE
(2021)
Article
Geosciences, Multidisciplinary
Qian Wang, Xianbo Su, Yi Jin, Peihong Chen, Weizhong Zhao, Shiyao Yu
Summary: This study investigates the pore structure of coal measure shale in the Sunan Syncline block. The results show that the shale has well-developed pores, mainly composed of clay minerals and quartz. The specific surface area of the pores is highest in those smaller than 5 nm, indicating their significant role in gas adsorption. The pore volume is mainly concentrated around 10 nm, contributing the most to pore volume and gas accumulation. The study also found that the content of organic carbon and clay minerals has a significant impact on the pore structure and shale porosity, with higher content leading to higher porosity.
FRONTIERS IN EARTH SCIENCE
(2022)
Article
Geosciences, Multidisciplinary
Zhanlei Wang, Bingzheng Guo, Chan Jiang, Lin Qi, Yuqiang Jiang, Yifan Gu, Yonghong Fu, Demin Liang
Summary: The Lower Permian Shanxi Formation in the Eastern Ordos Basin is a key target for shale gas exploration in China. This study used comprehensive methods to investigate the lithofacies and pore structure of the shale. The results showed that there are five different lithofacies types, with lithofacies V and lithofacies VI being the best in terms of pore morphology, connectivity, and development degree. Organic pore morphology was found to be closely related to the type of kerogen present, with sapropelinite contributing to better development of organic pores.
FRONTIERS IN EARTH SCIENCE
(2022)
Article
Chemistry, Multidisciplinary
Dangyu Song, Yu Qiao, Weiqing Liu, Xinbin Zhang, Zhen Yu, Guoqin Wei
Summary: This paper quantitatively characterized the nanopore structure of transitional shale and analyzed the origin of nanopores. The results showed that organic pores have an absolute advantage in methane adsorption in transitional shales.
Article
Energy & Fuels
Longfei Xu, Yishan Cheng, Jinchuan Zhang, Wei Dang, Yang Liu, Xuan Tang, Jialiang Niu, Zhongzheng Tong
Summary: The Shanxi Formation in the Ordos Basin is a potential stratum for shale gas reservoir, with a high proportion of methane indicating high maturity of source rocks. The carbon isotopic composition of the Shanxi Formation shale gas may be influenced by the complex sedimentary environment, multiple provenance systems, and high maturity.
JOURNAL OF PETROLEUM SCIENCE AND ENGINEERING
(2022)
Article
Geochemistry & Geophysics
Peng Zhang, Junwei Yang, Yuqi Huang, Jinchuan Zhang, Xuan Tang, Chengwei Liu
Summary: This study investigates the heterogeneity of the Longmaxi Formation shale from well Ld1 in western Hunan and Hubei. The shale is found to be composed mainly of siliceous shale, mixed shale, and clayey shale, with strong heterogeneity in terms of organic matter occurrence, mineral composition, microstructure, and pore types. The shale exhibits strong adsorption and gas storage capacity, but the pore structure is complex and connectivity is poor. This study emphasizes the importance of reservoir reformation measures during shale gas exploitation.
Article
Chemistry, Multidisciplinary
Yuanyuan Yang, Jinchuan Zhang, Longfei Xu, Pei Li, Yang Liu, Wei Dang
Summary: The pore structure characteristics of deep shale in the Shanxi Formation are studied, showing low pore surface area and pore volume, with mainly mesoporous pore diameter. The complexity of the pore structure is greater than that of the pore surface. The development of microfractures contributes to the pore development in the deep shale.
Article
Chemistry, Multidisciplinary
Fengzan Zheng, Xuan Tang, Kun Yuan, Tuo Lin, Mingxin You, Jialiang Niu, Yiyi Zi, Yutao Liang
Summary: China has achieved breakthroughs in shale gas production and discovered active shale oil and gas shows in Southern China. Detailed research on the sedimentology and organic matter enrichment mechanisms in these areas is crucial for understanding sedimentology and hydrocarbon exploration.
Article
Energy & Fuels
Zhen Li, Jinchuan Zhang, Xuanxue Mo, Zhongzheng Tong, Xianghua Wang, Dongsheng Wang, Zexin Su, Xuan Tang, Dajian Gong
Summary: This study investigates the storage behaviors of CH4 and CO2 in organic-rich shale by examining the angstrom-scale pores in 14 Lower Cambrian Niutitang shale samples. The results reveal the presence of different types of pores and their influence on gas storage. The study shows that CO2 has a higher storage volume in the angstrom scale than CH4, while CH4 has a higher ratio of the filling volume to the maximum adsorbed capacity. Additionally, higher pore heterogeneity leads to stronger CH4 and CO2 storage capacities.
Article
Geosciences, Multidisciplinary
Ziyi Liu, Dongxia Chen, Wenzhi Lei, Yang Liu, Guangjie Xie, Wei Dang, Xiuxiang Lv, Sha Li, Siyu Yuan
Summary: This study examines the factors controlling organic matter (OM) enrichment in lacustrine fine-grained rocks of the Jurassic Da'anzhai Member in the central Sichuan Basin. The results suggest that OM accumulation is mainly controlled by clastic input and sedimentation rate. The study also highlights the potential of siliceous shale as a lithology for unconventional hydrocarbon production in this region.
JOURNAL OF ASIAN EARTH SCIENCES
(2022)
Article
Geochemistry & Geophysics
Zhipeng Chen, Yanfei Yang, Caiyuan Dong, Ningxi Li, Pengtao Wang, Shaohua Zhang, Wei Dang, Yun Liao
Summary: This study evaluates the genesis and characteristics of the Cambrian dolomite in the Bachu area. The research shows that the dolomite mainly formed in a coeval seawater environment during the penecontemporaneous and shallow burial stages, and has undergone extensive recrystallization and burial diagenesis due to long-term deep burial.
Article
Geochemistry & Geophysics
Chenhui Wu, Xuan Tang, Xiaoguang Li, Bin Zhang, Pei Li, Zaixing Jiang, Yang Liu, Xiangfei Kong, Kefeng Du, Jinchuan Zhang
Summary: This study focused on the pore fluid distribution and behavior in shale pore system. Through the analysis of samples from the Chang 7 shale in the Ordos Basin, it was found that the pore channels in shale are mainly composed of clay mineral pores and micro-pores. Different types of pore fluids were found to occupy different pore-size ranges, with water occupying the mineral mesopores and oil and asphaltenes occupying organic-matter-hosted mesopores. The presence of pore fluid significantly impacts the pore structures of shale.
INTERPRETATION-A JOURNAL OF SUBSURFACE CHARACTERIZATION
(2023)
Article
Geosciences, Multidisciplinary
Hui Xiao, Nan Xie, Yuanyuan Lu, Tianyue Cheng, Wei Dang
Summary: The study of the pore structure and its controlling factors in shale reservoirs is crucial for the exploration and exploitation of shale gas. This study focused on the effects of organic and inorganic compositions on the pore structure development of Shanxi shale in the Ordos Basin. The results showed that the mineral composition and organic matter type are key factors in determining the pore structure of shale. The pore structure plays a significant role in the characteristics and development potential of shale.
FRONTIERS IN EARTH SCIENCE
(2022)
Article
Geosciences, Multidisciplinary
H. K. Nie, Q. Chen, P. Li, W. Dang, J. C. Zhang
Summary: The assessment of shale gas potential in the northwest margin of Ordos Basin in China focused on the Ordovician Pingliang Formation and Carboniferous-Permian Taiyuan and Shanxi formations. The study revealed the impact of fluctuating depositional environments on lithofacies and shale gas potential. By conducting various tests on representative samples, it was found that the Pingliang shale is a 'poor' source rock, while the transitional Taiyuan-Shanxi shales are characterized as 'fair' source rocks, with some samples showing good potential. The sedimentary environment plays a crucial role in the type and content of minerals in shale and ultimately controls the shale gas potential.
AUSTRALIAN JOURNAL OF EARTH SCIENCES
(2023)
Article
Energy & Fuels
Jiangtao Sun, Wei Dang, Fengqin Wang, Haikuan Nie, Xiaoliang Wei, Pei Li, Shaohua Zhang, Yubo Feng, Fei Li
Summary: In this study, three machine learning models (random forest, support vector regression, and XGBoost) were proposed to predict the TOC content using well logs. The results show that the random forest model provides the best predictive accuracy.
Article
Energy & Fuels
Ziheng Guan, Wei Liu, Xuewu Chen, Weibo Ma, Shaobin Guo, Xuan Tang
Summary: This study investigates the mineral composition, organic geochemical characteristics, and pore characteristics of low-mature shale samples. The results indicate that shale oil mobility is mainly controlled by the distribution of large-sized pores. Total organic carbon (TOC) content and lithofacies greatly influence the distribution of oil mobility in the shale. A new index is proposed to evaluate the content of shale oil, in situ oil saturation index (OSI), and multiple isothermal pyrolysis parameter S2-2.
Article
Energy & Fuels
Pei Li, Haikuan Nie, Jinchuan Zhang, Wei Dang, Reza Rezaee, Jianghui Ding, Qian Chen
Summary: This study investigates the reservoir properties of Permian Shanxi-Taiyuan shale and its heterogeneous wettability. It is found that organic petrology, organic geochemistry, mineralogy, and microstructure features significantly influence the wettability. The proposed triangle method and workflow for evaluating wettability can be applied in shale oil and gas exploration.
Article
Geochemistry & Geophysics
Fei Li, Wei Dang, Fengqin Wang, Haikuan Nie, Yubo Feng, Qiubo Liu, Jiangtao Sun, Yao Ma
Summary: This study measures gas release curves of shale and coal samples, revealing three curve patterns and finding correlations between released gas content and shale properties. It shows that the released gas content is strongly dependent on properties that control gas adsorption and diffusion capacity, such as organic matter content, specific surface area, and permeability. The study also indicates that the released gas during canister testing is mainly gas in the adsorbed state in reservoirs. These findings provide insightful information for gas-in-place evaluations and understanding of adsorbed/free gas dynamics.
Article
Chemistry, Multidisciplinary
Xiaoming Li, Xuan Tang, Shaobin Guo, Jinchuan Zhang, Ende Deng, Chaoli Lan
Summary: This study conducted a detailed survey of the outcrop and drill cores in the western Guizhou region to examine the distribution and geochemical characteristics of the Longtan Formation. The results showed that the shale in the Longtan Formation has a significant amount of total organic carbon and is mainly composed of vitrinite, clay minerals, and brittle minerals. The study identified eight types of lithofacies and six lithofacies assemblages, representing different sedimentary environments. The sedimentary model of the Longtan Formation in western Guizhou was predominantly deltaic and tidal flat systems.