东营凹陷沙河街组泥页岩中正丙基胆甾烷与异海绵烷的研究:硫循环对有机质富集的影响  

Study on n-propylcholestane and isorenieratane in the Shahejie black shales:Sulfur control on organic matter enrichment

作　　者：许汇源 侯读杰[3] Simon C George[4] 刘全有 Xu Huiyuan;Hou Dujie;Simon C George;Liu Quanyou(State Key Laboratory of Shale Oil and Gas Enrichment Mechanisms and Effective Development,Beijing,100083,China;Petroleum Exploration and Production Research Institute,SINOPEC,Beijing,100083,China;School of Energy Resources,China University of Geosciences,Beijing,100083,China;Department of Earth and Environmental Sciences,Macquarie University,Sydney 2109,Australia)

机构地区：[1]页岩油气富集机理与有效开发国家重点实验室,北京100083 [2]中国石油化工股份有限公司石油勘探开发研究院,北京100083 [3]中国地质大学(北京),能源学院,北京100083 [4]Department of Earth and Environmental Sciences,Macquarie University,Sydney 2109,Australia

出　　处：《南京大学学报（自然科学版）》2020年第3期366-381,共16页Journal of Nanjing University（Natural Science）

基　　金：中国博士后科学基金(2019M650968);国家自然科学基金(41472108,41625009)。

摘　　要：中国东部陆相渤海湾盆地东营凹陷古近系沙河街组油页岩中有机质的富集机制一直是研究热点,但关于异养生物及硫循环对有机质富集过程影响的研究较少.通过有机地球化方法对东营凹陷沙河街组第三、四段富有机质烃源岩进行精细研究,认为伴随着明显的水体分层,藻类勃发进一步加剧了底水缺氧的条件,海水带来了丰富的硫酸盐促进了强烈的细菌硫还原(Bacterial Sulfur Reduction,BSR)作用,将这种缺氧条件进一步扩展到水柱上部形成透光层缺氧(Photic Zone Euxinia,PZE),而PZE有利于光合自养绿硫菌的剧烈活动.强烈的BSR作用及间歇性的PZE控制东营凹陷古湖盆中藻类等水生生物的组成,原核细菌及海相金藻类对有机质富集有一定贡献.通过分析海相藻类生物标志物C3024-正丙基胆甾烷和透光层缺氧生物标志物异海绵烷与有机碳丰度的关系,研究认为在相对丰富的外源硫酸盐输入、厌氧异养细菌作用、光能自养细菌作用和透光层缺氧条件下形成的硫循环,对东营古湖盆沙河街组烃源岩有机质的富集起主要控制作用.The mechanism of orgnaic matter enrichment in the Shahejie Formation,Dongying Depression,Bohai Bay Basin,China has long been studied.However,controls of heterotrophic microorganism and sulfur cylce on the process of organic matter accumulation are seldom discussed.Here we present an organic geochemical study of black shales in the third and fourth member of the Shahejie Formation.Persistent water stratification,algal bloom and allothigenous(sea water)sulfate promote significant bacterial sulfate reduction(BSR),extending to photic zone euxinia(PZE).The PZE favors the activities of green/purple sulfur bacteria.Intense BSR and episodic PZE control the community structure of aquatic microorganism in the palaeolake,prokaryotic and marine Pelagophyte/Chrysophyte contribute to organic matter input.The relationship of total organic matter and C3024-n-propylcholestane and isorenieratane suggests that sulfur cycle in the presence of allothigenous sulfate,anaerobic heterotrophic bacterial reworking and PZE is the key to the organic matter enrichment in the Shahejie Formation,Dongying Depression.

关 键 词：渤海湾盆地 东营凹陷 正丙基胆甾烷 异海绵烷 透光层缺氧 海侵 硫循环 

分 类 号：TE122.113[石油与天然气工程—油气勘探]