国家冰川冻土沙漠科学数据中心

元数据

名称	Sulfur isotope of pyrite response to redox chemistry in organic matter-enriched shales and implications for components of shale gas
科技资源标识	CSTR:11738.14.NCDC.XDA14.PP5734.2024
DOI	10.1190/INT-2018-0023.1
数据共享方式	开放下载
摘要	The Sichuan Basin has achieved breakthroughs in shale gas production from the Upper Ordovician Wufeng and Lower Silurian Longmaxi Formation black shales. Large amounts of pyrite commonly occur in the organic matter (OM)-enriched black shales, but H2S has not been detected in the shale gas. The genetic mechanism of pyrite, its implications for redox chemistry, and the main controlling factors for the absence of H2S are unclear. The �34S values of the pyrite are extremely high. In particular, the nodular pyrite has �34S values as high as 38.6‰. The high sulfur isotopic values indicate that the Wufeng-Longmaxi Formation shales were deposited in an anaerobic sulfide euxinic environment where the limited SO42− in the stagnant bottom water was completely reduced to pyrite by bacterial sulfate reduction (BSR). The heavy sulfur isotope composition of the pyrite is indicative of organic-rich intervals, which are also the high-yielding intervals for shale gas. Shale gas from the Wufeng-Longmaxi Formation is dominated by alkanes, with an average CH4 content of 97.91%. The shale gas contains a small amount of CO2⁠, with an average of 0.34%. However, no H2S was detected. The �13CCO2 values have a range of 4.7‰–11.5‰, with an average of 7.8‰, which is significantly different from the CO2 related to thermochemical sulfate reduction (TSR) but similar to the CO2 from the decomposition of carbonate minerals. The black shales experienced high burial temperatures and were rich in OM, which met part of the necessary conditions for the occurrence of TSR. However, TSR did not occur. The reason for the lack of TSR process is that no sulfate mineral was available in the shales because the SO42− in the seawater was fully consumed by BSR. As a result, H2S associated with TSR was not detectable in the shale gas.
学科分类	170.50
关键词	fuling shale gas Wufeng-Longmaxi Formation pyrite sulfur isotope H2S BSR TSR
作者	Dongya Zhu,Quanyou Liu,Bing Zhou,Zhijun Jin,Tianyi Li
数据量	1.5 MiB
论文类型：	journal
论文网址：	https://doi.org/10.1190/INT-2018-0023.1
期刊名称：	Interpretation
出版时间：	2018-09-01

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数据引用

Dongya Zhu,Quanyou Liu,Bing Zhou,Zhijun Jin,Tianyi Li. Sulfur isotope of pyrite response to redox chemistry in organic matter-enriched shales and implications for components of shale gas. 国家冰川冻土沙漠科学数据中心(http://www.ncdc.ac.cn), 2024. https://cstr.cn/CSTR:11738.14.NCDC.XDA14.PP5734.2024.

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本作品采用知识共享署名 4.0 国际许可协议进行许可。

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项目信息详情

项目名称：深层油气形成与分布预测
项目编号：XDA14010000
项目类别：中国科学院战略性先导科技专项（A类）