鄂尔多斯盆地延长组烃源岩17α(H)-重排藿烷的组成及分布研究  

Composition and distribution of 17α(H)-diahopane in the Yanchang Formation source rocks,Ordos Basin

作　　者：邹贤利 陈世加[1,2] 路俊刚[1,2] 张海[1] 王力[1] 周世颖[1] ZOU Xian-li;CHEN Shi-jia;LU Jun-gang;ZHANG Hai;WANG Li;ZHOU Shi-ying(School of Geoscience and Technology, Southwest Petroleum University, Chengdu 610500, China;Sichuan Key Laboratory of Natural Gas Geology, Chengdu 610500, China)

机构地区：[1]西南石油大学地球科学与技术学院,四川成都610500 [2]四川省天然气地质重点实验室,四川成都610500

出　　处：《地球化学》2017年第3期252-261,共10页Geochimica

基　　金：国家重点基础研究发展计划项目(2014CB239005);国家自然科学基金(41572137;41502146);中石油创新基金(2015D-5006-0101)

摘　　要：以鄂尔多斯盆地陕北地区延长组下油层组烃源岩及储层抽提物为研究对象,探讨了17α(H)-重排藿烷和18α(H)-新藿烷系列化合物的分布规律、影响因素及在石油地质中的应用。鄂尔多斯盆地延长组湖相烃源岩普遍分布17α(H)-C_(30)重排藿烷(C_(30)DiaH),但研究区各层烃源岩之间C_(30)DiaH的相对丰度存在明显差异,深湖相缺氧环境的长7烃源岩相对丰度较低,而浅湖-半深湖相偏氧化环境的长7—长9黑色泥岩具有高-异常高的C_(30)DiaH。Ts、C29Ts、早洗脱重排藿烷与C_(30)DiaH之间表现出良好的正相关关系,说明在研究区重排藿烷类化合物可能与新藿烷系列具有相同的演化路径与形成机制。环境的氧化还原性和陆源的有机物来源等可能是制约17α(H)-重排藿烷相对丰度的主要因素,因此,不同油层组原油的17α(H)-重排藿烷相对丰度受到烃源岩的影响,用17α(H)-重排藿烷参数能很好地把研究区原油区分开来,为延长组不同油层的油源精细对比、油气富集规律和油气勘探提供可靠依据。Based on the analysis of source rock and reservoir extracts in the lower part of the Yanchang Formation in the Ordos Basin,North Shaanxi,this paper describes the distribution rules,influencing factors and applications in petroleum geology of17α(H)-diahopane and17α(H)-neohopane.Relatively high abundances of17α(H)-C30diahopane(C30DiaH)were detected in black mudstone,while various types of17α(H)-diahopane were observed in different hydrocarbon source rocks of the Yanchang Formation in the Ordos Basin.The results showed that the black mudstone was deposited under anoxic condition of semi-deep or deep lacustrine facies has a low abundance of C30DiaH in the Chang-7member.By comparison,the black mudstones with moderate-high abundances of C30DiaH in Chang-7member to Chang-9member were deposited under suboxic condition of shallow to semi-deep lacustrine facies.The extracts of black mudstones have moderate to high contents of C30DiaH with the high abundances of Ts,C29Ts and early-elution rearranged hopane,so the novel series of rearranged hopanes possibly has the same path and formation mechanism.The high concentrations of17α(H)-diahopane may have relationship with the sedimentary environment and organic matter type.Therefore,according to the relative abundances of17α(H)-diahopanes,the correlation between oil and source rocks was carried out in terms of17α(H)-diahopane parameters.The geochemical significance of17α(H)-diahopane lies in the fact that the oil-source correlation of the study area can be effectively solved,thus contributing to a better understanding of hydrocarbon generation and accumulation mechanisms and providing a better model for further petroleum exploration.

关 键 词：重排藿烷 烃源岩 沉积环境 油源对比 延长组 鄂尔多斯盆地 

分 类 号：P593[天文地球—地球化学]