Article
Engineering, Marine
Yanan Miao, Pengfei Wang, Xin Li, Haiping Huang, Can Jin, Wei Gao
Summary: Based on the drilling test results in northwest Hunan area, shale gas production in the Silurian Longmaxi Formation is higher compared to the Cambrian Niutitang Formation. This study used various methods to analyze the organic matter (OM) pore structure in core samples from both sets of shales. The analysis revealed that the two shales have similar reservoir characteristics but differ greatly in terms of OM pore shape. The thermal maturity and tectonic evolution process were identified as crucial factors affecting the OM pore evolution. The excessive evolution of organic matter in the Niutitang shale due to a large paleo-burial depth led to the disappearance of OM pores, while the insufficient hydrocarbon-generation evolution time in the Longmaxi shale prevented the formation of sufficient gaseous hydrocarbons and effective reservoir space. Consequently, the exploration and development potential of marine shale gas in these formations in northwest Hunan is poor.
JOURNAL OF MARINE SCIENCE AND ENGINEERING
(2023)
Article
Energy & Fuels
Luchuan Zhang, Dianshi Xiao, Shuangfang Lu, Guohui Chen, Tianyu Zhang, Shu Jiang, Lei Chen
Summary: In this study, high-pressure methane adsorption experiments were conducted on shale and kerogen samples from the Lower Longmaxi shale in the Nanchuan area, southeast Sichuan Basin, to investigate the supercritical methane adsorption properties. The results showed that the adsorbed methane density of kerogens obtained from the supercritical Dubinin-Radushkevich (SDR) model may be greater than the liquid methane density. The methane storage capacity was found to decline with increasing burial depth, while the free gas storage capacity showed the opposite trend. The significant contribution of organic matter (OM) to the methane adsorption capacity was attributed to the stronger affinity between kerogens and methane molecules compared to clay minerals (CMs) and whole shales.
Article
Geochemistry & Geophysics
Wei Wang, Dahua Li, Lijun Cheng, Ye Zhang, Jinxi Wang, Zhiping Zhang, Hualian Zhang, Dongxin Guo, Yuelei Zhang, Qing Hua, Jun Liu
Summary: This study provides a comprehensive assessment of the petrophysical characterization and gas accumulation of WL shale in the Sichuan Basin. The results indicate that the bottom section of the WL shale is better suited for hydraulic fracturing and has higher hydrocarbon generation ability and dry gas content.
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
Geosciences, Multidisciplinary
Qingsong Tang, Lu Zhou, Lei Chen, Xiucheng Tan, Gaoxiang Wang
Summary: The lithofacies types in the organic-rich Longmaxi shale in the Changning area of the southern Sichuan Basin were identified through various methods including thin sections, X-ray diffraction, and seismic data. The spatial variations in shale lithofacies were mainly controlled by palaeogeomorphology and relative sea level, with a vertical transition and lateral changes observed in the Long11 sub-member.
FRONTIERS IN EARTH SCIENCE
(2021)
Article
Energy & Fuels
Claudio Delle Piane, Humera Ansari, Zhongsheng Li, Jitendra Mata, William Rickard, Ronny Pini, David N. Dewhurst, Neil Sherwood
Summary: The study of porosity in the Fuling shale gas play in southern China revealed that the overall porosity in the samples is proportional to their organic content, with most pores residing in organic matter. Mesopores are preferentially present in solid bitumen, showing a broader spectrum of pore sizes in organic-rich samples. Furthermore, distinguishing between primary and secondary organic matter is crucial for understanding the interconnected network of porous organic matter during hydrocarbon migration.
INTERNATIONAL JOURNAL OF COAL GEOLOGY
(2022)
Article
Geosciences, Multidisciplinary
Jing Wu, Chao Liang, Renchao Yang, Jun Xie
Summary: This study examines the occurrence and importance of organic matter-mineral associations (OMMA) in shale gas reservoirs in the Sichuan Basin, identifying the impact of different types of OMMA on reservoir quality. The research also identifies four important lithofacies and highlights the heterogeneous distribution of OMMA in influencing hydrocarbon generation and gas storage conditions among different lithofacies.
MARINE AND PETROLEUM GEOLOGY
(2021)
Article
Geochemistry & Geophysics
Ang Li, Siyuan Su, Xuesong Li, Jiahao Zhang, Cui Jing, Zhenduo Zhao
Summary: This study investigates the characteristics of graphitized shale and the impact of organic matter graphitization on shale gas accumulation. The results show that organic matter graphitization is a result of thermal metamorphism, leading to lower resistivity in graphitized shale. The graphitization of organic matter can damage hydrocarbon generation and reservoir capacity, resulting in reduced gas content. The brittleness of graphitized shale increases, and the destruction of organic and intercrystalline pores leads to deterioration of reservoir physical properties. Graphitized organic matter has good electrical conductivity, explaining the formation of low-resistivity shale. Early hydrocarbon generation, poor reservoir physical properties, and unfavorable preservation are the main factors contributing to the low gas content of graphitized shale.
Article
Geosciences, Multidisciplinary
Yadong Zhou, Zhanlei Wang, Dongfeng Hu, Zhihong Wei, Xiangfeng Wei, Ruobing Liu, Daojun Wang, Yuqiang Jiang
Summary: By studying Dongyuemiao lacustrine shale in the Eastern Sichuan Basin, it is found that organic pores consist of primary pores within plant debris and secondary pores within bitumen. Inorganic pores are composed of intraparticle pores within calcite particles, intercrystalline pores between pyrite crystals, and interparticle pores between different minerals. The 4th Section lacustrine shale of Dongyuemiao Member has the best pore structure, with high organic pore proportion, large amounts of gas adsorption, and parallel plate-shaped pore morphology. Micropores are the main contributors to the pore volume and surface area of Dongyuemiao lacustrine shale. The enrichment of organic matter positively affects the formation of micropores and has no influence on the mesopore-macropore. Quartz does not significantly affect the nanoscale pore formation. The intraparticle pores within calcite particles constitute part of the mesopore-macropore but not micropores. Clay minerals are conducive to the formation of micropores but play a negative role in the formation of the mesopore-macropore.
FRONTIERS IN EARTH SCIENCE
(2023)
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
Jing Wu, Chao Liang, Ren-Chao Yang, Zongquan Hu, Wenjin Li, Jun Xie
Summary: The Late Ordovician-Early Silurian sedimentary succession in the Sichuan Basin, China, provides valuable information about the changes in sedimentary environments. The mineral composition and lithofacies of the shales in this region reflect these changes. The study analyzes the main minerals present (quartz, clay minerals, and carbonate) and identifies five major lithofacies. By examining various proxies, such as provenance indicators, chemical index of alteration, paleoproductivity proxies, redox condition indicators, proxies of detrital influx, and sedimentation rate, the paleoenvironment is analyzed. The study reveals the relationship between environmental changes and shale mineral composition and lithofacies.
JOURNAL OF ASIAN EARTH SCIENCES
(2022)
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
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
Geosciences, Multidisciplinary
Yang Wang, Hongfei Cheng, Qinhong Hu, Luofu Liu, Lewei Hao
Summary: The study investigated the impact of diagenesis on pore systems in different lithofacies of Wufeng-Longmaxi shale from Sichuan Basin, China. Different lithofacies showed varying diagenetic pathways and evolution of pore systems under the same burial history. Diagenesis played a crucial role in determining the final status of the initial pore space and controlling the distribution of migrated OM, influencing the development of dominant OM pores in the entire pore spectrum.
MARINE AND PETROLEUM GEOLOGY
(2021)
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
Geosciences, Multidisciplinary
Weijiao Ma, Jinbu Li, Min Wang
Summary: The petroleum resource assessment obtained from laboratory tests on old core samples tends to underestimate the in situ resources. This study investigates the hydrocarbon loss and restoration by comparing preserved and exposed core samples. It is found that previous studies have severely underestimated the in situ hydrocarbon potential due to factors such as sample crushing and crucible waiting. A new restoration model is proposed to compensate for these losses.
MARINE AND PETROLEUM GEOLOGY
(2024)
Article
Geosciences, Multidisciplinary
Shaoyun Chen, Yongqiang Yang, Longwei Qiu, Xiaojuan Wang, Erejep Habilaxim
Summary: Quartz cement is an important authigenic mineral in the tight sandstones of the Shaximiao Formation in the Sichuan Basin. This study analyzed the silicon sources of the quartz cement using mineralogical, fluid inclusion, and geochemical data. The results showed that smectite alteration and dissolution of aluminosilicate minerals were the primary sources of silicon for quartz cementation. Contributions from volcanic material hydrolysis and pressure solution were relatively minor. The presence of chlorite films inhibited the development of quartz overgrowths and had minimal impact on reservoir quality.
MARINE AND PETROLEUM GEOLOGY
(2024)
Article
Geosciences, Multidisciplinary
Xing Jian, Ping Guan, Ling Fu, Wei Zhang, Xiaotian Shen, Hanjing Fu, Ling Wang
Summary: This study presents a synthesis of new detrital zircon dating results and published data from the Cenozoic Qaidam basin, revealing the spatiotemporal variation of detrital zircon age populations and supporting models of synchronous deformation in northern Tibet. The study emphasizes the importance of considering textural and sedimentological parameters in zircon provenance interpretations, as well as the need for integrated provenance analysis involving other detritus components.
MARINE AND PETROLEUM GEOLOGY
(2024)
Article
Geosciences, Multidisciplinary
A. Peketi, G. Sriram, A. Mazumdar, P. Dewangan, A. Zatale, V. Rajurkar, Gayatri Shirodkar, V. Mahale, V. Yatheesh
Summary: This study investigates 13 submarine seamounts in the southern Andaman volcanic arc and observes evidence of hydrothermal activity in one of the seamounts. The evidence includes plumes rich in dissolved gases, live chemosymbiotic organisms, and the deposition of neoforming minerals. These observations suggest the development of a new hydrothermal field in the least explored Andaman Sea.
MARINE AND PETROLEUM GEOLOGY
(2024)
Article
Geosciences, Multidisciplinary
Yanxian Zhu, Zhiliang He, Xiaowen Guo, Long Li, Sheng He, Jian Gao, Shuangjian Li, Huili Li
Summary: This study investigates the fluid evolution history of the hydrothermal dolomite reservoir in the Middle Permian Maokou Formation in the Sichuan Basin. The results reveal the diagenetic sequences, mineral origins, salinity history, and pressure evolution using various analytical techniques. The findings provide important insights into the gas charge, escape, and preservation conditions of the reservoir.
MARINE AND PETROLEUM GEOLOGY
(2024)
Article
Geosciences, Multidisciplinary
Rafaella de Carvalho Antunes, Julia Campos Guerrero, Ricardo Jorge Jahnert
Summary: This study presents a detailed sedimentary model and identifies various sedimentary facies associations in the coquina deposits of the Itapema Formation in the offshore pre-salt Buzios Field of the Santos Basin. These facies associations were primarily influenced by waves and currents and reflect a complex depositional system.
MARINE AND PETROLEUM GEOLOGY
(2024)
Article
Geosciences, Multidisciplinary
Kang Meng, Tongwei Zhang, Deyong Shao, Xiuyan Liu, Hui Song, Heng Peng
Summary: In this study, an integrated method of measuring optical reflectance and Raman spectroscopy is proposed to accurately determine the thermal maturity of Lower Cambrian shales in South China. The results show that this method is reliable and effective, and it has important implications for analyzing overmature shale.
MARINE AND PETROLEUM GEOLOGY
(2024)
Article
Geosciences, Multidisciplinary
Mohamed A. K. El-Ghali, Olga Shelukhina, Iftikhar Ahmed Abbasi, Mohamed S. H. Moustafa, Osman Salad Hersi, Numair A. Siddiqui, Khalid Al-Ramadan, Abdullah Alqubalee, Abdulwahab Muhammad Bello, Abduljamiu O. Amao
Summary: This study employs an integrated depositional and sequence stratigraphic approach to assess the control of diagenesis on reservoir porosity of a hybrid-energy delta system. The study focuses on the Barik Formation in the Haushi-Huqf region of Central Oman, which represents a highstand system tract of a hybrid-energy delta. The assessments reveal that the reservoir porosity is controlled by various degrees of diagenetic processes, including mechanically infiltrated clays and kaolinitization of silicate grains.
MARINE AND PETROLEUM GEOLOGY
(2024)
Article
Geosciences, Multidisciplinary
Xiaocan Yu, Chunlian Wang, Hua Huang, Kai Yan
Summary: Oilfield brines are a significant alternative lithium resource. This study investigates the metallogenic characteristics and enrichment process of oilfield brines from the Jianghan Basin, central China using chemical and multi-isotope data. The results suggest that lithium enrichment in these brines is the result of interaction with clastic host rocks and dilution by meteoric water.
MARINE AND PETROLEUM GEOLOGY
(2024)
Article
Geosciences, Multidisciplinary
Jianghao Qiao, Xiwu Luan, Thanuja D. Raveendrasinghe, Yintao Lu, Guozhang Fan, Xinyuan Wei, Long Jin, Jian Yin, Haozhe Ma, Lushan Jiang
Summary: This study investigates the Tanintharyi passive continental margin in the Andaman Sea and reveals the potential of the Oligocene/Early Miocene carbonate platform in the region as a significant hydrocarbon reservoir. It also examines the influence of changes in sedimentary facies and the tectonic setting of the Andaman Sea on the evolution of pockmarks.
MARINE AND PETROLEUM GEOLOGY
(2024)
Article
Geosciences, Multidisciplinary
Anastasios Nikitas, Georgios Makrodimitras, Maria V. Triantaphyllou, Nikolaos Pasadakis, Kimon Christanis, Stavros Kalaitzidis, Grigoris Rousakis, Ioannis Panagiotopoulos, Alexandra Gogou, Alexandros Papadopoulos, Efthimios Tartaras, Aristofanis Stefatos
Summary: Due to the lack of deep wells in the broader region, studying mud volcanic deposits can improve the geological understanding of the Mediterranean Ridge. In this study, biostratigraphic and geochemical analyses were performed on mud breccia deposits from five Mud Volcanoes in the central MR. The results indicate the origin of these deposits and provide insights into the source rock potential. Seismic data is also used to determine the distribution of major lithostratigraphic formations.
MARINE AND PETROLEUM GEOLOGY
(2024)