气候变化领域集成服务门户(CCPortal): Influence of tectonic exhumation on porosity of Wufeng-Longmaxi shale in the Fuling gas field of the eastern Sichuan Basin; China

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DOI	10.1306/08161918071
	Influence of tectonic exhumation on porosity of Wufeng-Longmaxi shale in the Fuling gas field of the eastern Sichuan Basin; China
	Liu R.; Liu R.; Hao F.; Hao F.; Engelder T.; Shu Z.; Yi J.; Xu S.; Teng C.
发表日期	2020
ISSN	0149-1423
起始页码	939
结束页码	959
卷号	104 期号:4
英文摘要	Thermal cracking of organic matter (OM) can enhance gas-shale porosity. However, thermally matured shales are generally characterized by low porosity with high OM content in tectonic exhumation settings. The Wufeng-Longmaxi shale in the Fuling gas field, China, was investigated via bulk analysis and scanning electron microscopy to reveal the influence of tectonic exhumation on the porosity of OM-rich shale. Thermal maturity and organic and mineralogical compositions are regionally homogeneous in the Fuling gas field. Shale porosity is positively correlated with total organic carbon (TOC) and clay mineral content in the gentle and open anticlines, respectively. The OM-hosted pores were preserved with spherical morphologies because of overpressure-associated overburden stress unloading in the gentle anticlines, whereas OM-hosted pores in the open anticlines are characterized by high aspect ratios and are regularly aligned perpendicular to lateral compression stress. A simple simulation confirmed that tectonic folding and compaction during exhumation caused the loss of porosity in the inner arcs of the open anticlines. Only pressure shadows formed by assemblages of clay mineral platelets and mechanically competent grains inhibited tectonic compaction of some OM-hosted pores in the open anticlines. Tectonic compaction of porosity generally increased the mean value of water saturation in the open anticlines. The extremely high water saturation (>60%) in the high-TOC interval (>2 wt. %) was generally associated with natural fractures, suggesting the occurrence of gas leakage. © 2020 The American Association of Petroleum Geologists. All rights reserved.
语种	英语
scopus关键词	Aspect ratio; Clay minerals; Compaction; Gases; Organic carbon; Scanning electron microscopy; Structural geology; Tectonics; Unloading; High aspect ratio; Lateral compression; Mineralogical compositions; Overburden stress; Spherical morphologies; Tectonic exhumation; Total Organic Carbon; Water saturations; Porosity; clay mineral; compaction; compression; cracking (fracture); electron microscopy; exhumation; folding; gas field; organic matter; overburden; porosity; pressure; saturation; shale; total organic carbon; China; Chongqing; Fuling Gas Field; Sichuan; Sichuan Basin; Taiwan; Wufeng
来源期刊	AAPG Bulletin
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/143711
作者单位	School of Geoscience and Technology, Southwest Petroleum University, Chengdu, Sichuan, China; Department of Geosciences, Pennsylvania State University, University Park, PA, United States; Key Laboratory of Tectonics and Petroleum Resources, Ministry of Education, China University of Geosciences, Wuhan, Hubei, China; School of Geosciences, China University of Petroleum, Qingdao, Shandong, China; Department of Geosciences, Pennsylvania State University, University Park, PA, United States; Sinopec Jianghan Oilfield Company, Qianjiang, Hubei, China
推荐引用方式 GB/T 7714	Liu R.,Liu R.,Hao F.,et al. Influence of tectonic exhumation on porosity of Wufeng-Longmaxi shale in the Fuling gas field of the eastern Sichuan Basin; China[J],2020,104(4).
APA	Liu R..,Liu R..,Hao F..,Hao F..,Engelder T..,...&Teng C..(2020).Influence of tectonic exhumation on porosity of Wufeng-Longmaxi shale in the Fuling gas field of the eastern Sichuan Basin; China.AAPG Bulletin,104(4).
MLA	Liu R.,et al."Influence of tectonic exhumation on porosity of Wufeng-Longmaxi shale in the Fuling gas field of the eastern Sichuan Basin; China".AAPG Bulletin 104.4(2020).