Study on the Mechanism of Organic Matter Enrichment in Early Cambrian Marine Shales in the Lower Yangtze Area, South China: An Example Using Well JXY1
The abundance of organic matter in shales, which has a direct effect on the hydrocarbon generation potential of shales, is an important organic geochemical parameter for evaluating shale gas reservoirs. The total organic carbon content (TOC content) in shale is controlled by the abundance of origina...
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| Format: | Article |
| Language: | English |
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Wiley
2020-01-01
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| Series: | Geofluids |
| Online Access: | http://dx.doi.org/10.1155/2020/2460302 |
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| author | Sihong Cheng Bin Li Kun Zhang Weiwei Liu Jun Peng Mingcai Hou Ming Wen Qingsong Xia Xin Wang Xiaoxue Liu Li Zhong Yizhou Huang Yongyang Liu Muhe Yuan Yue Yao |
| author_facet | Sihong Cheng Bin Li Kun Zhang Weiwei Liu Jun Peng Mingcai Hou Ming Wen Qingsong Xia Xin Wang Xiaoxue Liu Li Zhong Yizhou Huang Yongyang Liu Muhe Yuan Yue Yao |
| author_sort | Sihong Cheng |
| collection | DOAJ |
| description | The abundance of organic matter in shales, which has a direct effect on the hydrocarbon generation potential of shales, is an important organic geochemical parameter for evaluating shale gas reservoirs. The total organic carbon content (TOC content) in shale is controlled by the abundance of original sedimentary organic matter. Therefore, it is very important to study the mechanism of organic matter enrichment in shale. In this paper, the Lower Cambrian marine shales from the Lower Yangtze region are selected as the research subject, most of which originate from a typical area well called Well JXY1. The degree of pyritization (DOP) is used to characterize the redox environment of the water body, while the P/Al ratio is used to analyze the biological productivity of paleoseawater. The paleosalinity of seawater is calculated via carbon and oxygen isotope analysis. In addition, the early Cambrian hydrothermal activities were studied by using core description; Si, Al, Fe, and Mn elemental analysis; and oxygen isotope calculations. The results show that during the early Cambrian Wangyinpu sedimentary period, the seawater was an anaerobic water body with H2S, and the oxygen concentration was approximately 0 mL/L. In the middle stages of the Wangyinpu sedimentary period, the water body had the strongest reducibility and the highest biological productivity. Moreover, the paleoocean in this period between the Yangtze plate and the Cathaysian plate was greatly affected by hydrothermal activities, with temperatures ranging from 90°C to 120°C. Active hydrothermal activities promoted high biological productivity and an anaerobic environment, both of which were conducive to the preservation and enrichment of organic matter, resulting in extremely high TOC content in the Wangyinpu shales (from 6.5% to approximately 16%). |
| format | Article |
| id | doaj-art-08d3349591e241b79fb8334aeb698f0c |
| institution | Kabale University |
| issn | 1468-8115 1468-8123 |
| language | English |
| publishDate | 2020-01-01 |
| publisher | Wiley |
| record_format | Article |
| series | Geofluids |
| spelling | doaj-art-08d3349591e241b79fb8334aeb698f0c2025-02-03T01:04:22ZengWileyGeofluids1468-81151468-81232020-01-01202010.1155/2020/24603022460302Study on the Mechanism of Organic Matter Enrichment in Early Cambrian Marine Shales in the Lower Yangtze Area, South China: An Example Using Well JXY1Sihong Cheng0Bin Li1Kun Zhang2Weiwei Liu3Jun Peng4Mingcai Hou5Ming Wen6Qingsong Xia7Xin Wang8Xiaoxue Liu9Li Zhong10Yizhou Huang11Yongyang Liu12Muhe Yuan13Yue Yao14Institute of Sedimentary Geology, Chengdu University of Technology, Chengdu 610059, ChinaSchool of Geoscience and Technology, Southwest Petroleum University, Chengdu 610500, ChinaSchool of Geoscience and Technology, Southwest Petroleum University, Chengdu 610500, ChinaJiangxi Provincial Shale Gas Investment Company, Ltd., Nanchang 330000, ChinaSchool of Geoscience and Technology, Southwest Petroleum University, Chengdu 610500, ChinaInstitute of Sedimentary Geology, Chengdu University of Technology, Chengdu 610059, ChinaState Key Laboratory of Petroleum Resources and Prospecting, China University of Petroleum, Beijing 102249, ChinaSchool of Geoscience and Technology, Southwest Petroleum University, Chengdu 610500, ChinaState Key Laboratory of Petroleum Resources and Prospecting, China University of Petroleum, Beijing 102249, ChinaState Key Laboratory of Petroleum Resources and Prospecting, China University of Petroleum, Beijing 102249, ChinaSchool of Geoscience and Technology, Southwest Petroleum University, Chengdu 610500, ChinaOrganic Geochemistry Unit, School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, UKSchool of Geoscience and Technology, Southwest Petroleum University, Chengdu 610500, ChinaSchool of Geoscience and Technology, Southwest Petroleum University, Chengdu 610500, ChinaSchool of Geoscience and Technology, Southwest Petroleum University, Chengdu 610500, ChinaThe abundance of organic matter in shales, which has a direct effect on the hydrocarbon generation potential of shales, is an important organic geochemical parameter for evaluating shale gas reservoirs. The total organic carbon content (TOC content) in shale is controlled by the abundance of original sedimentary organic matter. Therefore, it is very important to study the mechanism of organic matter enrichment in shale. In this paper, the Lower Cambrian marine shales from the Lower Yangtze region are selected as the research subject, most of which originate from a typical area well called Well JXY1. The degree of pyritization (DOP) is used to characterize the redox environment of the water body, while the P/Al ratio is used to analyze the biological productivity of paleoseawater. The paleosalinity of seawater is calculated via carbon and oxygen isotope analysis. In addition, the early Cambrian hydrothermal activities were studied by using core description; Si, Al, Fe, and Mn elemental analysis; and oxygen isotope calculations. The results show that during the early Cambrian Wangyinpu sedimentary period, the seawater was an anaerobic water body with H2S, and the oxygen concentration was approximately 0 mL/L. In the middle stages of the Wangyinpu sedimentary period, the water body had the strongest reducibility and the highest biological productivity. Moreover, the paleoocean in this period between the Yangtze plate and the Cathaysian plate was greatly affected by hydrothermal activities, with temperatures ranging from 90°C to 120°C. Active hydrothermal activities promoted high biological productivity and an anaerobic environment, both of which were conducive to the preservation and enrichment of organic matter, resulting in extremely high TOC content in the Wangyinpu shales (from 6.5% to approximately 16%).http://dx.doi.org/10.1155/2020/2460302 |
| spellingShingle | Sihong Cheng Bin Li Kun Zhang Weiwei Liu Jun Peng Mingcai Hou Ming Wen Qingsong Xia Xin Wang Xiaoxue Liu Li Zhong Yizhou Huang Yongyang Liu Muhe Yuan Yue Yao Study on the Mechanism of Organic Matter Enrichment in Early Cambrian Marine Shales in the Lower Yangtze Area, South China: An Example Using Well JXY1 Geofluids |
| title | Study on the Mechanism of Organic Matter Enrichment in Early Cambrian Marine Shales in the Lower Yangtze Area, South China: An Example Using Well JXY1 |
| title_full | Study on the Mechanism of Organic Matter Enrichment in Early Cambrian Marine Shales in the Lower Yangtze Area, South China: An Example Using Well JXY1 |
| title_fullStr | Study on the Mechanism of Organic Matter Enrichment in Early Cambrian Marine Shales in the Lower Yangtze Area, South China: An Example Using Well JXY1 |
| title_full_unstemmed | Study on the Mechanism of Organic Matter Enrichment in Early Cambrian Marine Shales in the Lower Yangtze Area, South China: An Example Using Well JXY1 |
| title_short | Study on the Mechanism of Organic Matter Enrichment in Early Cambrian Marine Shales in the Lower Yangtze Area, South China: An Example Using Well JXY1 |
| title_sort | study on the mechanism of organic matter enrichment in early cambrian marine shales in the lower yangtze area south china an example using well jxy1 |
| url | http://dx.doi.org/10.1155/2020/2460302 |
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