羌塘盆地胜利河地区布曲组油气地球化学特征与油源对比  

Petroleum Geochemical Characteristics and Oil Source Correlation of Buqu Formation in Shenglihe Area,Qiangtang Basin

作　　者：刘天夫 季长军[3] LIU Tianfu;JI Changjun(PetroChina Usmile Company Limited,Beijing 102200;Northeast Petroleum University,Daqing,Heilongjiang 163318;Chinese Academy of Geological Sciences,Beijing 100037)

机构地区：[1]中石油昆仑好客有限公司,北京102200 [2]东北石油大学,黑龙江大庆163318 [3]中国地质科学院,北京100037

出　　处：《地球学报》2024年第3期365-374,共10页Acta Geoscientica Sinica

基　　金：中国地质调查局地质调查项目(编号:DD20230315);中国地质科学院基本科研业务费项目(编号:JKY202209);国家自然科学基金目(编号:41602122)联合资助。

摘　　要：羌塘盆地胜利河地区侏罗系海相地层的地表露头有大量的油气显示。以往研究表明该地区发育多套含油气系统,油气性质复杂。本次研究在前人工作基础上,以中侏罗统布曲组(J2b)中部油页岩露头、探井岩心的油气显示以及地表油气显示为主要研究对象。通过TOC分析、岩石热解、饱和烃色谱和饱和烃色谱-质谱的分析,更为详细地研究了胜利河地区烃源岩类型,对原油来源进行了进一步探讨,为该地区下一步油气勘探工作提供更多的理论依据。研究表明,该地区J2b组中部油页岩有机质类型以Ⅱ型为主,具有较高的生油潜力。该地区原油主要来源于还原性海相沉积环境。研究区样品的有机质输入主要以低等水生生物为主, DB4142以低等水生生物和高等植物混合贡献,BD4902以高等植物输入为主。原油处于成熟阶段,所有样品均检测出25-降藿烷系列的化合物,指示样品均遭受了较为强烈的生物降解作用。依据生物标志物指纹特征和生物标志化合物参数特征,运用聚类分析方法,将研究区原油划分为A、B、C、D四类。其中A类原油主要来自于同层位(J2b)的烃源岩,而B、C、D类原油没有或者很少有该套烃源岩(J2b)的贡献,可能来自其它层位烃源岩贡献。Surface outcrops of Jurassic marine strata in the Shenglihe area of the Qiangtang Basin contain a large amount of petroleum.Previous research indicated the presence of multiple petroleum systems with complex properties.Based on previous research,the main research objects of this study were the petroleum display of the central oil shale outcrop,exploration well core,and surface oil and gas display of the Middle Jurassic Buqu Formation(J2b).Through TOC analysis,rock pyrolysis,saturated hydrocarbon chromatography,and saturated hydrocarbon chromatography-mass spectrometry,the source rock types and oil sources in the Shenglihe area were studied in detail,providing a theoretical basis for further petroleum exploration.The results show that the organic matter within the J2b middle stratum was primarily Type II,which has a high potential for oil generation.The oil predominantly originates from reduced marine sedimentary environments.The organic matter input of the samples in the study area was mainly lower aquatic organisms;DB4142 was mixed with lower aquatic organisms and higher plants;and BD4902 mainly contained higher plants.The oil reached maturity,as evidenced by 25-norholane series compounds in all the samples,suggesting a history of significant biodegradation.Using cluster analysis based on fingerprint and biomarker parameter characteristics,we classified the oil into four categories:A,B,C,and D.Class A oil mainly comes from the source rocks of the same horizon(J2b),whereas Classes B,C,and D exhibit little to no contribution from the J2b source rocks and may come from other horizon source rocks.

关 键 词：羌塘盆地 烃源岩 生物标志化合物 地球化学 油源对比 

分 类 号：P618.13[天文地球—矿床学]