Article
Energy & Fuels
Chima Finnian Ukaomah, Mengdi Sun, Zhejun Pan, Mehdi Ostadhassan, Bo Liu, Yanran Xu, Agwom Istifanus Madaki, Happiness Ijeoma Umeobi, Mohammed Dahiru Aminu, Baolin Yang
Summary: In this study, the gas storage capacity and CO2 sequestration suitability of the Longmaxi and Niutitang shale gas reservoirs were compared. The results showed that the Longmaxi shale has higher storage capacity and better pore connectivity, indicating its potential for CO2 storage and enhanced gas recovery (EGR).
Article
Geosciences, Multidisciplinary
Zhongliang Ma, Jingqiang Tan, Lunju Zheng, Baojian Shen, Zhanghu Wang, Asim Shahzad, Irfan U. Jan, Hans-Martin Schulz
Summary: The study evaluated the generation and preservation potential of shale gas in the Wufeng-Longmaxi Formation shale by conducting semiclosed hydrous pyrolysis experiments, finding that retained oil is the primary source of gas and a TOC content of 1.5% meets the evaluation standard for favorable marine shale gas play areas in China.
MARINE AND PETROLEUM GEOLOGY
(2021)
Article
Energy & Fuels
Ping Gao, Xianming Xiao, Dongfeng Hu, Ruobing Liu, Yidong Cai, Tao Yuan, Guangming Meng
Summary: This study investigated the water content and its distribution in the different nanopores of deep and ultra-deep shales in China. The results showed that irreducible water is the dominant form of water in ultra-deep shales, primarily occurring in clay-hosted pores and parts of organic pores. It is mainly distributed in non-micropores, especially in micropores with a diameter of 0.4-0.6 nm and mesopores with a diameter of 2-10 nm. The presence of irreducible water significantly affects the specific surface area of non-micropores, which is more pronounced in organic-rich shale samples.
Article
Energy & Fuels
Ruolong Chi, Ping Gao, Yidong Cai, Ruobing Liu, Jinghan Du, Qin Zhou
Summary: This study investigated the types and development characteristics of pores in the ultra-deep organic-rich shale reservoirs of the Eastern Sichuan Basin. The results showed that the dominant pore types were organic pores, mineral matrix pores, and micro-fractures. The development of organic pores was influenced by the content of organic matter and brittle minerals, with higher contents contributing to their development and preservation.
Article
Geosciences, Multidisciplinary
Tonglou Guo, Xianghao Meng, Wei Lei, Mingming Liu, Liang Huang
Summary: This study conducted systematic experimental characterization to understand the pore structures and methane sorption in deep-marine shales. The results showed that factors such as organic matter content and clay minerals affect the pore structures and sorption behaviors in deep shales. The findings also indicate that deep shales have higher micropore content from organic matter and lower macropore content from clay minerals compared to shallow shales. The total organic carbon (TOC) content is the primary controlling factor on pore structure and sorption capacity in deep shales, while the influence of clay minerals on gas sorption is less pronounced.
NATURAL RESOURCES RESEARCH
(2023)
Article
Geochemistry & Geophysics
Kui Xiang, Liangjun Yan, Gongxian Tan, Yuanyuan Luo, Gang Yu
Summary: This study investigated the electrical anisotropy characteristics of shale reservoirs in southern Sichuan, exploring the influencing factors and laws of complex resistivity anisotropy, and established an evaluation model. The research results have formed a set of testing methods and analysis techniques for electrical anisotropy of shale reservoirs, mainly based on complex resistivity parameter testing.
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
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
Or Aimon Brou Koffi Kablan, Tongjun Chen
Summary: In this study, the pore pressure prediction for the Wufeng-Longmaxi shale in the Sichuan Basin was conducted using the Eaton-Yale approach. By integrating various data and modeling techniques, the pore pressure values were determined and overpressure zones were corrected, providing a basis for reservoir simulation models and permeability prediction.
Article
Geochemistry & Geophysics
Jianlin Guo, Chengye Jia, Dongbo He, Fankun Meng
Summary: The study proposed classification criteria for net pay of shale gas reservoirs in the Shunan area of the Sichuan Basin, based on the analysis of porosity, gas saturation, density of rock, brittleness index, and gas content. The application of gas content and brittleness index parameters reflects reservoir resource basis and fracability respectively. The net pay can be classified into three types based on the ranges of these two parameters, with implications for testing production and economic benefits.
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
Geosciences, Multidisciplinary
Yongbo Wei, Shuangfang Lu, Junqian Li, Rongze Yu, Wenbiao Li, Feng Cheng, Chunbo Fu, Tianlong Zhao, Wenjun Feng, Zhaojing Song
Summary: The study investigates methane carbon isotope fractionation during shale gas desorption, revealing the impact of various factors on the process and providing insights into evaluating gas content and production status in shale gas wells.
MARINE AND PETROLEUM GEOLOGY
(2021)
Article
Geosciences, Multidisciplinary
Zhen Qiu, Bei Liu, Bin Lu, Zhensheng Shi, Zhiyang Li
Summary: This study focused on the depositional and diagenetic processes controlling the fabric and petrophysical properties of black shales through the analysis of the Wufeng-Longmaxi Shale. It was found that the studied shale is mainly composed of over-mature black shales with organic matter dominated by pyrobitumen and graptolite, while minerals consist of quartz, carbonates, and clay minerals. Vertical variations in lithofacies and mineral content exhibited three cycles, likely corresponding to three transgressive-regressive cycles.
MARINE AND PETROLEUM GEOLOGY
(2022)
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
Geosciences, Multidisciplinary
Haikuan Nie, Zhijun Jin, Pei Li, Barry Jay Katz, Wei Dang, Quanyou Liu, Jianghui Ding, Shu Jiang, Donghui Li
Summary: Deep shale gas at a burial depth greater than 3500 m in China is an important potential target for exploration and development. This study systematically investigates the spatial distribution, reservoir types and properties, preservation conditions, and gas content of deep shale gas in the Sichuan Basin. It is recommended to establish a volume fracturing plan and optimize production systems with excellent pressure management procedures to maximize deep shale gas production and achieve commercial development.
JOURNAL OF ASIAN EARTH SCIENCES
(2023)
Article
Geochemistry & Geophysics
Pengwei Wang, Zhongbao Liu, Xiao Chen, Dongjun Feng, Ruyue Wang, Zeyang Peng
Summary: The study investigates the impact of coexisting clay mineral and organic matter on pore growth in the Da'anzhai Shale reservoir, revealing that the pore system is dominated by clay-mineral-hosted pores, with organic pores influenced by pyrobitumen filling. The pore system in the shale reservoir is controlled by the coexistence of clay mineral and pyrobitumen, affecting pore size, shape, and volume.
INTERPRETATION-A JOURNAL OF SUBSURFACE CHARACTERIZATION
(2021)
Article
Geochemistry & Geophysics
Fuqiang Lai, Yuejiao Liu, Xiaopan Kou, Zhaohui Huang, Zhen Chen, Yuanqi Liu, Guoqiang Jiang, Yongqian Zang, Min Wang, Ruyue Wang, Martina Zucchi
Summary: In this study, the pore characteristics of tight sandstone reservoirs were determined using NMR and high-pressure mercury injection experiments. A method for fluid identification was developed and showed better performance in identifying high-resistivity water layers compared to conventional methods.
Article
Geochemistry & Geophysics
Shuang Wang, Zhonghu Wu, Jun Chen, Hao Liu, Ruyue Wang, Jingshou Liu
Summary: This study analyzed the mineralogical composition of shale cores from a well in northern Guizhou and investigated the impact of mineral components on the permeability impairment rate and stress sensitivity coefficient of shale reservoirs. The results showed that clay mineral content and effective stress were negatively correlated with permeability and porosity, while detrital mineral content was positively correlated. Quartz content and modulus of elasticity were negatively correlated with permeability impairment rate and stress sensitivity factor, while clay mineral content was positively correlated. Shale with higher brittle mineral content was more likely to undergo brittle damage and exhibited lower stress sensitivity factor.
Article
Energy & Fuels
Gang Zhao, Wenlong Ding, Jing Tian, Jingshou Liu, Yang Gu, Siyu Shi, Ruyue Wang, Ning Sun
Summary: The study investigated the correlations between elemental, mineral contents, and mechanical parameters of shale in the Lower Cambrian Niutitang Formation in the Fenggang block of northeastern Guizhou. It was found that within certain ranges of silicon content, there were significant positive/negative correlations between static Young's modulus, shear modulus, bulk modulus, and brittleness index with silicon content, clay, and quartz, feldspar, and mica contents. There is uncertainty in determining rock mechanical parameters within certain elemental content ranges, indicating the need for more mathematical models and factors to adequately characterize those parameters.
JOURNAL OF PETROLEUM SCIENCE AND ENGINEERING
(2022)
Article
Energy & Fuels
Gang Zhao, Zhijun Jin, Wenlong Ding, Guangxiang Liu, Jinbiao Yun, Ruyue Wang, Guanping Wang
Summary: The study on fractures in the Wufeng-Longmaxi Formation in Hunan Province reveals that these fractures can be divided into different types based on their combination characteristics and roughness. The fractures mainly occurred in the late Yanshanian-Himalayan period and experienced repeated processes of splitting, healing, and re-splitting. The gas migration and enrichment in these fractures play a key role in the distribution and preservation of shale gas.
JOURNAL OF PETROLEUM SCIENCE AND ENGINEERING
(2022)
Article
Geochemistry & Geophysics
Fuqiang Lai, Xiaoxue Xia, Changjiang Wang, Ruyue Wang, Lulu Zhong, Zhaohui Huang, Haitao Wang, Zhangxiong Zhu
Summary: This study analyzed the pore types and structures of shale gas reservoirs in the Zhaotong national shale gas demonstration area in the southern margin of the Sichuan Basin through various experimental methods. Organic matter pores and clay mineral interlamellar pores were found to be the main pore types in marine shale gas reservoirs in the study area. Furthermore, the total organic carbon content was positively correlated with the complexity and heterogeneity of reservoir pores.
INTERPRETATION-A JOURNAL OF SUBSURFACE CHARACTERIZATION
(2022)
Article
Geochemistry & Geophysics
Wenchao Fang, Xuejie Qin, Chuanxi Liu, Ruyue Wang, Jun Pu, Hanqiao Jiang, Weiling He
Summary: Understanding the relationship between petroleum recovery and characteristics of hydraulic fracture network is crucial for the economic development of tight reservoirs. This study investigates the effect of fracture density and fracture connectivity on reservoir behavior and well production using a new discrete fracture simulator. The simulations reveal that increasing fracture density or fracture connectivity significantly improves well production, with fracture connectivity playing a more important role. In tight reservoirs with abundant natural fractures, placing horizontal wells parallel to the direction of natural fractures is determined to be the optimal strategy.
Article
Geosciences, Multidisciplinary
Weiling He, Ruyue Wang, Qiqi Lyu, Jun Liu, You Wu
Summary: The fine-grained sedimentary rock reservoirs in the Late Triassic Yanchang Formation in the Ordos Basin in central China have great potential for tight oil production. Through comprehensive analysis of various characteristics and experiments, it was found that the reservoir experienced processes such as compaction, cementation, and dissolution. The burial history analysis revealed three phases of oil charging in the reservoir. The role of organic acid and the protective effect of chlorite membrane inhibited the densification process of the reservoir.
FRONTIERS IN EARTH SCIENCE
(2022)
Article
Geosciences, Multidisciplinary
Xinghua Wang, Ruyue Wang, Rongtao Guo, Arash Dahi Taleghani, Shuaitao Su, Wenlong Ding, Yue Gong, Fuqiang Lai, Zhonghu Wu, Yushan Su, Zhe Cao
Summary: The marine shale of southern China is characterized by a complex fracture system, which greatly adds to the difficulties in shale gas exploration and development. This study examines the developmental characteristics of fractures in the Cen'gong block and finds that fracture abundance is closely related to buried depth and regional faults in the study area.
FRONTIERS IN EARTH SCIENCE
(2022)
Article
Geosciences, Multidisciplinary
Xuehui Zhou, Ruyue Wang, Zhili Du, Jing Wu, Zhonghu Wu, Wenlong Ding, Ang Li, Zikang Xiao, Zixian Cui, Xinghua Wang
Summary: Based on the observations and testing data, this paper discusses the characteristics and controlling factors of fractures and their control on shale gas accumulation in the Lower Cambrian Niutitang Formation black shale reservoir of Well YX1 in the northern Guizhou Province. The results show that various types of fractures are present in the Niutitang Formation, and their formation is mainly controlled by major faults. Compared to other shale gas reservoirs, the Well YX1 reservoir has both geological sweet spots and engineering sweet spots, but deformation and faulting have caused the loss of shale gas and damage to the overpressure environment.
FRONTIERS IN EARTH SCIENCE
(2022)
Article
Geochemistry & Geophysics
Zhonghu Wu, Shuang Wang, Jun Chen, Huailei Song, Wentao Wang, Ruyue Wang, Hao Liu
Summary: This study investigates the impact of quartz content on fracture expansion in shale reservoirs. Numerical simulations and physical tests were used to analyze shale models with different quartz contents. The results show that a quartz content of 50% to 65% leads to higher compressive strength and fracture proportion. Fractures occur within the shale matrix or at the junctions of the shale matrix and quartz grains. The fractal dimension is higher for a quartz content of 50% to 65%.
Article
Geochemistry & Geophysics
Ran Tan, Ruyue Wang, Yahao Huang, Rui Yang, Hongbo Li, Kuan Lu
Summary: This study investigates the effect of different fractures on shale gas construction or destruction by analyzing fracture cements in the Silurian-Ordovician shale formations in the southern Sichuan Basin. The geochemical investigations reveal the diagenetic mineral sequences, paleo-pressure recovery, and diagenetic fluid environments. It is found that bedding slippage fractures enhance shale gas enrichment, while high-angle shear fractures disrupt the shale sealing. The study also examines the trapping conditions and periods of gas accumulation through the analysis of CH4-bearing fluid inclusions. Results show that pore fluid pressure and pressure coefficient in the shale reservoirs have significantly reduced due to tectonic activities and strata uplift-erosion.
Article
Geochemistry & Geophysics
Xuan Wang, Ruyue Wang, Jianping Bai, Na Zhang, Haoting Xing, Michael Kamoto, Weiling He
Summary: This study characterizes the sedimentary fabric and formation environment of dendrolites in the Cambrian Zhangxia Formation in Zibo, Shandong Province, and analyzes its genetic mechanism. It has great significance for studying microbial carbonate in geological history and its implications for oil exploration.
Article
Geochemistry & Geophysics
Yuejiao Liu, Fuqiang Lai, Ruyue Wang, Zhonghu Wu, Xiaoshu Zhang, Hao Xu, Jiao Li
Summary: This paper discusses the brittleness characteristics and controlling factors of continental shale in the Da'anzhai Member of the Ziliujing Formation in the northeast Sichuan Basin. Carbonate minerals play a significant role in controlling the brittleness of continental shale, and the presence of shell limestone interlayers and laminates greatly improves the reservoir's brittleness.
Article
Geochemistry & Geophysics
Yuejiao Liu, Haitao Wang, Fuqiang Lai, Ruyue Wang, Haijie Zhang, Xiaoshu Zhang, Fahui Ou
Summary: A 3D digital core model was constructed to simulate the influences of gas saturation, mineral composition, stratification, and fractures on Poisson's ratio in a shale gas reservoir. The results showed that stratification dip angle and fracture dip angle had the greatest impact on Poisson's ratio, reaching its minimum value when the angles were close to 45 degrees. Poisson's ratio was most sensitive to the content of calcite and least influenced by gas saturation. The average error between the measured and simulated Poisson's ratio was 4.920%.
