南羌塘盆地侏罗系砂糖状白云岩古油藏油源研究——来自芳烃化合物和单体烃碳同位素的证据  

Crdue oil source of granulated dolomite paleo-reservoir from the Jurassic strata in the South Qiangtang Basin:Evidence from carbon isotopes ofaromatic compounds and monomeric hydrocarbons

作　　者：唐友军[1,2] 张欣越 季长军 王霆 何大祥[1,2] 杨易卓[1,2] 孙鹏 李博偲 裴冰冰[1,2] TANG Youjun;ZHANG Xinyue;JI Changjun;WANG Ting;HE Daxiang;YANGYizhuo;SUN Peng;LI Bocai;PEI Bingbing(Hubei Key Laboratory of Petroleum Geochemistry and Environment(Yangtze University),Wuhan 430100,Hubei;Key Laboratory of Exploration Technologies for Oil and Gas Resources,Ministry of Education(Yangtze University),Wuhan 430100,Hubei;Institute of Geomechanics,Chinese Academy of Geological Sciences,Beijing 100037)

机构地区：[1]油气地球化学与环境湖北省重点实验室(长江大学),湖北武汉430100 [2]油气资源与勘探技术教育部重点实验室(长江大学),湖北武汉430100 [3]中国地质科学院地质力学研究所,北京100037

出　　处：《长江大学学报（自然科学版）》2022年第2期1-11,共11页Journal of Yangtze University(Natural Science Edition)

基　　金：国家自然科学基金项目“苯基多环芳烃检测及其石油地球化学意义”(41972148);中国地质科学院项目“羌塘盆地隆鄂尼—鄂斯玛地区油气地质构造调查”(DD20160161)。

摘　　要：近些年关于南羌塘盆地侏罗系砂糖状白云岩古油藏的油源问题一直存在着较大的争议,主要原因是降解作用对常规的饱和烃化合物以及参数产生了较大的影响。芳烃和正构烷烃单体碳同位素抗生物降解能力强,且蕴藏反映油藏的成烃母质来源、成烃环境以及热成熟度等多方面地质地球化学信息。对砂糖状白云岩古油藏以及油源可能性较高的上三叠统与中下侏罗统烃源岩样品抽提物中的芳烃馏分进行了GC-MS分析,并且采用GC-IRMS仪器对其中的正构烷烃单体碳、氢同位素进行测定,旨在揭示古油藏以及相关烃源岩芳烃化合物和单体碳同位素的组成与分布特征。研究表明,南羌塘盆地古油藏可分为2类:Ⅰ类古油藏,甲基菲指数相对较高、高硫芴低氧芴以及单体碳同位素相对较重,表征以高等植物碎屑贡献为主,且形成于还原沉积环境下的成熟有机质,为上三叠统扎那组烃源岩;Ⅱ类古油藏,甲基菲指数相对较小,三芴系列具有高氧芴低硫芴的分布特征和相对较轻的单体烃碳同位素特征,表明其来源于有机质以低等水生藻类和细菌为主,并沉积于弱还原条件下的低熟成熟下侏罗统曲色组的烃源岩。上述研究进一步证实了南羌塘盆地上三叠统扎那组和下侏罗统曲色组具备良好的油气资源前景。In recent years,there has been a lot of controversy about the oil source of the Jurassic sugar-like dolomite paleo-reservoir in the South Qiangtang Basin,mainly because the degradation has a great influence on the conventional saturated hydrocarbon compounds and parameters.The carbon isotopes of aromatic hydrocarbons and n-alkanes have strong resistance to biodegradation,and they contain geological and geochemical information that reflects the source of hydrocarbon-forming parent materials,hydrocarbon-forming environment and thermal maturity of the reservoir.The aromatic hydrocarbon fractions in the extracts from the sugar-like dolomite paleo-reservoirs and the the Upper Triassic and Middle-lower Jurassic source rock samples with high oil potential were analyzed by GC-MS.The GC-IRMS instrument was used to measure the carbon and hydrogen isotopes of n-alkanes,so as to reveal the composition and distribution characteristics of aromatic hydrocarbon compounds and monomeric carbon isotopes in paleo-reservoirs and related source rocks.Studies have shown that paleo-reservoirs in the South Qiangtang Basin can be divided into two categories:TypeⅠis paleo-reservoirs with relatively high methyl phenanthrene index,high sulfur fluorene and low oxygen fluorene,and relatively heavy monomeric carbon isotopes,characterized by mature organic matter mainly contributed by higher plant detritus and formed in a reducing sedimentary environment,as hydrocarbon source rocks of the Upper Triassic Zana Formation.TypeⅡis paleo-reservoirs with relatively small methyl phenanthrene index.The trifluorene series have the distribution characteristics of high oxygen fluorene and low sulfur fluorene,and have relatively light monomeric hydrocarbon carbon isotope characteristics,indicating that its origin is mainly from organic matter with low aquatic algae andbacteria,and it is deposited in the source rocks of low-mature-mature Lower Jurassic Quse Formation under weakreducing conditions.The above studies further confirm that the Upper Triassic Z

关 键 词：南羌塘盆地 古油藏 芳烃化合物 单体烃碳同位素 油源对比 

分 类 号：TE122[石油与天然气工程—油气勘探]