Article
Energy & Fuels
Zhang Bin, Mao Zhiguo, Zhang Zhongyi, Yuan Yilin, Chen Xiaoliang, Shi Yuxin, Liu Guanglin, Shao Xiaozhou
Summary: Based on geochemical analysis results of core samples from the Triassic Chang 7 Member of Well Feng 75 in the northwest margin of Ordos Basin, the study comprehensively investigates the formation environment of black shale and its control on shale oil enrichment, indicating the impact of continental volcanic activity on negative drift of carbon isotopic composition in black shale.
PETROLEUM EXPLORATION AND DEVELOPMENT
(2021)
Article
Geochemistry & Geophysics
Bojiang Fan, Xinyang Dai, Chi Wang
Summary: This study comprehensively compared and analyzed the geochemical characteristics of desorption gas in the Chang 7 Member shale. The results showed that the shale gas mainly consists of CH4, C2H6, and C3H8. Porosity, permeability, and organic matter content are the main geological factors controlling gas migration and hosting. Shale with higher porosity, good permeability, and lower organic matter content is conducive to gas migration. The sandy laminated shale with a higher gas content may be the sweet spot of shale gas targets.
Article
Energy & Fuels
Jiyuan You, Yiqun Liu, Yijun Li, Dingwu Zhou, Qinghua Zheng, Yiyao Yang, Jian Shi, Haofeng Gao
Summary: The Chang 7 oil shales in the Triassic Yanchang Formation show significant positive anomalies in Cs, U, Th, Pb, and Mn, and negative anomalies in Eu and Ta. The TOC values vary across different sections, and there is a strong correlation between hydrothermal input intensity and TOC content.
JOURNAL OF PETROLEUM SCIENCE AND ENGINEERING
(2021)
Article
Geochemistry & Geophysics
Wang Zhang, Xinping Liang, Peng Li, Guoheng Liu, Jin Qian
Summary: Significant amounts of unconventional oil and gas resources have been discovered in the Yanchang Formation of Ordos Basin, primarily sourced from the shale layers in Chang 7 and 9 members. The C7-3 submember shale has the highest content of illite/smectite mixed layer and reducing minerals, while the C9 member shale has the highest percentage of quartz and illite. The C7-3 submember shale is characterized by high productivity due to type II1 kerogen, and the C9 member shale exhibits the highest organic thermal maturity.
Article
Energy & Fuels
Qiulei Guo, Yue Yao, Lianhua Hou, Shuheng Tang, Songqi Pan, Feng Yang
Summary: This study investigates the retention, migration, and accumulation of oil in a lacustrine shale system from the Upper Triassic Yanchang Formation, Ordos Basin. The research findings demonstrate the impact of lithofacies on oil composition and amount stored in the shale systems. Organic-rich shale lithofacies retain a large amount of oil, while thin organic-lean siltstones act as reservoir units for migrated petroleum. The study also reveals the influence of pore structure on oil retention and migration.
INTERNATIONAL JOURNAL OF COAL GEOLOGY
(2022)
Article
Energy & Fuels
Jinqi Qiao, Alireza Baniasad, Laura Zieger, Chen Zhang, Qun Luo, Ralf Littke
Summary: The study indicates that the Chang 7 member is a typical clay-rich source rock deposited in a sulphate-poor lacustrine to fluvio-deltaic environment under oxic to sub-oxic conditions, with organic matter mainly derived from higher land plants, mainly conifers. The studied samples show a thermal maturity within the oil window, with average Tmax values around 445 degrees Celsius, showing some regional variability within the mid-western Ordos Basin.
INTERNATIONAL JOURNAL OF COAL GEOLOGY
(2021)
Article
Energy & Fuels
Guanping Wang, Qian Zhang, Rukai Zhu, Xuan Tang, Kouqi Liu, Zhijun Jin
Summary: The main pore space in the lacustrine Chang 7 Shale is dominated by macro- and meso-pores, while the pores within organic matter are rarely observed. Quartz promotes the development of macro- and meso-pores, while clay minerals show negative effects on their heterogeneity. A critical maturity point of 0.8% Ro is observed for the change of the pore system, and both fractal dimensions and pore structure proxies show inverse trends before and after this point. These findings contribute to a better understanding of pore system evolution and identification of high-quality reservoirs in lacustrine shales.
GEOENERGY SCIENCE AND ENGINEERING
(2023)
Article
Geochemistry & Geophysics
Zhiwei Liao, Zigang Wu, Qiang Chen, Yi Zhang, Xiaodong Wang, Yunqian Liu, Zhijie Xu
Summary: This study analyzed drilling samples from the Tianhuan Depression in the western Ordos Basin to understand the organic matter enrichment mechanism, hydrocarbon potential, and paleoenvironment of the Late Triassic Yanchang Formation's 7th member. The results showed that the Chang 7(3) sub-member has ultra-high organic matter abundance, good hydrocarbon generation potential, and was deposited in a warm and humid paleoclimate setting. Factors such as high productivity, terrigenous organic matter input, and transgression contributed to the extreme organic matter enrichment in the study area. However, compared to other regions in the Ordos Basin, the Chang 7(3) sub-member in the central Tianhuan Depression is not a suitable target for shale oil exploration.
Article
Geosciences, Multidisciplinary
Ningliang Sun, Tianyu Chen, Jianhua Zhong, Jianbo Gao, Xueyao Shi, Chunqi Xue, Rudy Swennen
Summary: This study examines the lithologic and geochemical characteristics of organic-rich mudstones and shales in the Chang 7 member of the Yanchang Formation. The results show that these rocks contain abundant brittle minerals and high organic matter content, making them suitable for hydraulic fracturing and shale oil exploration.
JOURNAL OF ASIAN EARTH SCIENCES
(2022)
Article
Geosciences, Multidisciplinary
Hao Lu, Qing Li, Dali Yue, Yue Wu, Jian Gao, Shenghe Wu, Wurong Wang, Mingqiang Li, Keqin An
Summary: The heterogeneity of shale pore structure is a crucial factor influencing shale oil exploration and development. Organic-rich laminated shale (ORLS) and organic-poor layered shale (OPLS) exhibit significant differences in pore system heterogeneity. ORLS has higher porosity and permeability compared to OPLS, and its pore system shows wider pore size range and stronger holistic distribution heterogeneity. The volume of micropores and macropores is higher in ORLS, while the surface area and volume of mesopores are lower. The macropore in ORLS displays the most obvious fractal characteristics. The mineral composition, laminae, TOC content, thermal evolution degree, and fluid pathways control the evolution patterns of shale reservoirs. The macropore volume in ORLS is positively correlated with pyrite content, and the development degree of secondary dissolution plays a crucial role in determining the reservoir qualities of ORLS and OPLS.
MARINE AND PETROLEUM GEOLOGY
(2023)
Article
Geography, Physical
Mingtao Yao, Zuoyu Sun, Qingqiang Meng, Jiachun Li, Dayong Jiang
Summary: The study revealed that the early Ladinian lacustrine ecosystem of the Ordos Basin is the earliest known Mesozoic-type, trophically multileveled lake ecosystem after the end-Permian mass extinction. Vertebrate coprolites from the Chang 7 Member showed evidence of piscivorous animals as producers, enriching the biodiversity of the ecosystem with large carnivorous predators. The presence of apex predators in a trophically multileveled lake ecosystem suggests the rebuilding of the top-predator trophic structure after the end-Permian mass extinction.
PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY
(2022)
Article
Geosciences, Multidisciplinary
Wei Yu, Jingchun Tian, Feng Wang, Qingshao Liang, Tian Yang, Benjamin Kneller, Xiaowei Liang
Summary: The black mudstone of the Chang-7 Member in the Ordos Basin is the most important source rock with good hydrocarbon generation potential. The sedimentary environment was semi-arid and semihumid, with continental freshwater, and an average paleotemperature of 16 degrees C. The medium-high primary productivity and suitable sedimentary environment played important roles in the enrichment and preservation of organic matter in the Chang-7 Member.
JOURNAL OF ASIAN EARTH SCIENCES
(2022)
Article
Geosciences, Multidisciplinary
Lianhua Hou, Xia Luo, Senhu Lin, Zhongying Zhao, Yong Li
Summary: This study proposes a method to accurately calculate the retained oil content in organic-rich shale in the Ordos Basin. The method resulted in significantly higher oil content measurements compared to traditional methods, providing important guidance for the analysis of retained oil and shale oil reserve evaluations. Positive correlations were found between total retained oil content and mineral compositions, with the method showing reliable results for the evaluation of shale oil reserves.
FRONTIERS IN EARTH SCIENCE
(2021)
Article
Energy & Fuels
Yuan-Yuan Zhang, Ke-Lai Xi, Ying-Chang Cao, Bao-Hai Yu, Hao Wang, Mi-Ruo Lin, Ke Li, Yang-Yang Zhang
Summary: An approach combining conventional log data, mineral composition prediction, and lamina combination type identification based on machine learning was successfully applied to predict shale lamina combinations in the Chang 73 sub-member in Yanchang Formation of Ordos Basin. The results validated the effectiveness of this method in identifying the types of shale lamina combinations and understanding the planar distribution characteristics of the laminae in the study area.
Article
Geosciences, Multidisciplinary
Bojiang Fan
Summary: The Triassic Yanchang Formation in the central Ordos Basin, China, has shown great potential as a shale oil/gas play, with six wells currently producing more than 5 tons of oil per day. This study aimed to understand the controlling factors for organic matter enrichment in the Chang-7 shale and the environmental conditions under which it was deposited. Comprehensive lithological, organic geochemical, and element analyses revealed that the Chang-7 shale is primarily composed of massive to laminated shales and was deposited in a shallow to semi-deep lake environment. The shale has a high organic carbon content and is in a moderate thermal evolutionary stage, making it a moderate to high-quality source rock. The organic matter in the shale has a mixed source, including in situ production and terrestrial input from rivers.
NATURAL RESOURCES RESEARCH
(2022)
Article
Biodiversity Conservation
Zhen Guo, Zhong-Qiang Chen, David A. T. Harper, Yuangeng Huang
Summary: The Rhynchonellida, a group of brachiopods, showed increased lineage richness in the Early and early Middle Triassic with changes in shell size and development of ornamentation. The study suggests that paedomorphosis might have been a survival strategy for certain genera to thrive in the harsh environment after the P/Tr extinction.
Article
Geography, Physical
Chen Han, Michael J. Orchard, Shunling Wu, Laishi Zhao, Zhong-Qiang Chen, Martyn L. Golding, Irfan U. Jan, Zhengyi Lyu, Syed Hashmi
Summary: This study focused on the morphological changes and ontogenetic series of important Griesbachian-Dienerian conodonts based on well-preserved specimens from northwestern Pakistan. By reconstructing their phylogenetic relationships and analyzing morphometric data, the study identified complex evolutionary trends and heterochronic patterns in platform growth. The reduction of platform in late Griesbachian species was attributed to progenesis and neoteny, while the Dienerian segminate conodonts exhibited postdisplacement of the flange. Additionally, the study suggested that the Dienerian Neospathodus lineage represented a paedomorphosis of the flange, while the Sw. kummeli-Eu. costatus lineage may have undergone peramorphosis of the platform through acceleration.
GLOBAL AND PLANETARY CHANGE
(2022)
Article
Geosciences, Multidisciplinary
Hao Yang, Zhong-Qiang Chen, Dominic Papineau
Summary: Stromatolites, one of the oldest life forms on Earth, have been found in the Jixian area of North China. These stromatolites, known as micro-digitate stromatolites (MDSs), have been debated for their biogenicity due to the lack of convincing microfossils. However, new evidence from the Wumishan Formation suggests that the MDSs are likely fossilized prokaryotes. Spheroids, filamentous microfossils, and nano-particles have been identified in the Wumishan MDSs, indicating the contribution of diverse filamentous and coccoidal micro-organisms to their formation.
PRECAMBRIAN RESEARCH
(2022)
Review
Engineering, Multidisciplinary
Caineng Zou, Zhen Qiu, Jiaqiang Zhang, Zhiyang Li, Hengye Wei, Bei Liu, Jianhua Zhao, Tian Yang, Shifa Zhu, Huifei Tao, Fengyuan Zhang, Yuman Wang, Qin Zhang, Wen Liu, Hanlin Liu, Ziqing Feng, Dan Liu, Jinliang Gao, Rong Liu, Yifan Li
Summary: The commercial exploitation of unconventional petroleum resources has significantly transformed the global energy structure. Sweet-spot intervals, consisting of deposits with high organic matter content or closely associated sandstones/carbonate rocks, are the most productive unconventional hydrocarbon resources. The formation of sweet-spot intervals is controlled by depositional and diagenetic settings influenced by global or regional geological events. Understanding the formation and distribution of sweet-spot intervals is crucial for unconventional petroleum systems.
Editorial Material
Geosciences, Multidisciplinary
Caineng Zou, Zhi Yang, Guoxin Li, Jianzhong Li, Xianyang Liu, Yong Tang, Tao Jiang, Yu Yang, Xuefeng Bai, Songqi Pan, Minghui Lu, Zhengdong Lei, Bo Cai
JOURNAL OF EARTH SCIENCE
(2022)
Editorial Material
Geosciences, Multidisciplinary
Caineng Zou, Youliang Feng, Zhi Yang, Wenqi Jiang, Songqi Pan, Tianshu Zhang, Xiaoni Wang, Jichang Zhu, Jiarui Li
JOURNAL OF EARTH SCIENCE
(2022)
Article
Geosciences, Multidisciplinary
Zhi Yang, Caineng Zou, Songtao Wu, Songqi Pan, Xiaoni Wang, Haitao Liu, Wenqi Jiang, Jiarui Li, Qiyan Li, Xiaobing Niu, Guohui Li, Zhenxing Tang, Xuguang Guo, Dong Huang, Qizhao Wei
Summary: The sweet sections in giant shale oil provinces in China are important areas that support the increase in reserves and production of continental shale oil. These regions have favorable geological conditions for oil and gas accumulation, and their evaluation is based on key parameters such as hydrocarbon generation and reservoir capacities. The development of geological sweet sections in these provinces has contributed to the rapid growth of the shale oil industry in China, providing an important supplement to domestic oil production.
JOURNAL OF EARTH SCIENCE
(2022)
Article
Geosciences, Multidisciplinary
Yinghao Jing, Zhong-Qiang Chen, Ross P. Anderson, Xue Wang, Zemin Zheng, Xueqian Feng
Summary: This study investigates the Tonian Longfengshan biota in Hebei Province, North China using various microscopic and geochemical analysis techniques. The results show that the fossil specimens are preserved as carbonaceous patches and have high calcium content. Iron-rich clay minerals are also associated with the fossils. The integration of data suggests that the fossil-bearing shale was deposited in the subtidal zone below storm wave base, and the degradation process of the fossils may have been inhibited by iron-replete but sulfate-depleted porewater.
PRECAMBRIAN RESEARCH
(2022)
Article
Biochemistry & Molecular Biology
Yuangeng Huang, Zhong-Qiang Chen, Peter D. Roopnarine, Michael J. Benton, Laishi Zhao, Xueqian Feng, Zhenhua Li
Summary: The history of Earth's biodiversity has been marked by periodic mass extinctions, with major declines in species richness. However, the accompanying ecological collapse has seldom been quantitatively evaluated. The Permian-Triassic mass extinction, as the largest known extinction event, permanently changed marine ecosystems and facilitated the transition from the Paleozoic to Mesozoic faunas. This extinction event provides insight into the relationship between species richness and ecological dynamics during severe extinctions, but the ecological collapse during this event has not been thoroughly examined.
Article
Geography, Physical
Kunio Kaiho, Stephen E. Grasby, Zhong-Qiang Chen
Summary: A series of environmental extreme events and mass extinctions were discovered at the Guadalupian-Lopingian boundary (GLB), which may have been caused by volcanic eruptions of the Emeishan large igneous province (LIP). The study suggests that volcanic activity related to the Emeishan LIP may have led to these environmental extreme events and mass extinctions.
PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY
(2023)
Article
Geosciences, Multidisciplinary
Xue Wang, Yinghao Jing, Huan Peng, Hao Yang, Zhenli Zhu, Zhong-Qiang Chen
Summary: This study investigates the Cadmium isotopes from the Xiamaling Formation in North China to evaluate the nutrient utilization and paleo-productivity in the 1.4 Ga ocean. The results show variations in delta 114Cd values, indicating changes in nutrient utilization rate and redox conditions. However, nutrient consumption in the ocean was still incomplete, slowing down the evolution of phytoplanktons in the 1.4 Ga ocean in the North China Craton.
PRECAMBRIAN RESEARCH
(2023)
Article
Geography, Physical
Shunling Wu, Chen Han, Martyn L. Golding, Zhong-Qiang Chen, Zhengyi Lyu, Laishi Zhao
Summary: This study presents integrated conodont biostratigraphy and carbon isotope analysis of the Permian-Triassic boundary (PTB) beds and Lower Triassic succession in the Baoshan block. The dominant conodont faunas in the dolomitized Hewanjie Formation are Hindeodus and Isarcicella species, along with Eurygnathodus and the Ellisoniidae. The conodont zones and carbon isotope profile are consistent with those from other well-documented sections worldwide. The study also indicates a shallow water-depth based on conodont biofacies analysis.
PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY
(2023)
Article
Geography, Physical
Zhengyi Lyu, Charles M. Henderson, Zhong-Qiang Chen, Jinnan Tong, Laishi Zhao, Chen Han, Shunling Wu
Summary: A precise global timescale for the Lower Triassic Series is essential for understanding the sequence of events following the mass extinction. The recognition of an Induan-Olenekian boundary (IOB) is crucial for establishing a high-resolution chronostratigraphic framework for this interval. Recent research on conodont biostratigraphy has led to a refined definition of the IOB, with proposed markers for the boundary. Rating: 8
PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY
(2023)
Article
Multidisciplinary Sciences
Zhen Guo, Joseph T. Flannery-Sutherland, Michael J. Benton, Zhong-Qiang Chen
Summary: Using Bayesian analyses, this study finds that brachiopods and bivalves displayed similar large-scale trends of diversification before the Jurassic period. The extinction of major brachiopod clades during the Permian-Triassic mass extinction set the stage for the switch from brachiopods to bivalves, with high ocean temperatures post-extinction further facilitating the displacement of brachiopods by bivalves.
NATURE COMMUNICATIONS
(2023)
Article
Energy & Fuels
Caineng Zou, Songtao Wu, Zhi Yang, Songqi Pan, Guofeng Wang, Xiaohua Jiang, Modi Guan, Cong Yu, Zhichao Yu, Yue Shen
Summary: Carbon dioxide storage and utilization has become an inevitable trend and choice for sustainable development due to global climate change and carbon neutrality. The carbon industry, which focuses on CO2 capture, utilization, and storage (CCUS/CCS), is emerging as a strategic industry under the goal of carbon neutrality. The development of a low-cost and energy-efficient carbon industry system based on CCUS/CCS is crucial for achieving carbon neutrality and clean energy utilization globally.
PETROLEUM EXPLORATION AND DEVELOPMENT
(2023)