天草凹陷天2井油砂地球化学特征与油源研究  

Geochemical Characteristics and Origin of Oil Sand of Tian 2 Well,Tiancao Sag

作　　者：唐友军[1] 文志刚[2] 张超漠[3] 李军[3] 朱翠山[2] 

机构地区：[1]中国石油大学石油与天然气成藏机理教育部重点实验室,北京102249 [2]长江大学地球化学系,湖北荆州434023 [3]长江大学油气资源与勘探技术教育部重点实验室,湖北荆州434023

出　　处：《地质科技情报》2007年第4期47-52,共6页Geological Science and Technology Information

基　　金：湖北省教育厅重点项目(B200512001);长江大学油气资源与勘探技术教育部重点实验室开放基金项目(K200616);长江大学校基金项目

摘　　要：天草凹陷天2井油气显示丰富。以天2井油砂为剖析对象,采用定量色谱-质谱技术,从定性和定量两个角度精细剖析了油砂的生物标志物组合特征。油砂中C31～C35藿烷丰度依次降低,伽马蜡烷丰度较高,无重排藿烷和重排甾烷,C27～C29规则甾烷呈反“L”型分布,C28甾烷丰度较高。甾烷的异构化成熟度参数、甲基菲指数均显示油砂成熟度低。在对该区可能烃源岩生物标志物组合特征分析的基础上,从生物标志物指纹及其丰度特征确认了油砂与下白垩统巴音戈壁组下段烃源岩有成因联系,进一步明确了巴音戈壁组下段烃源岩为天草凹陷的主力烃源岩。Tian 2 well shows its richness in crude oil and gases. By using quantitative chromatography-mass spectrometry, we analyzed the biomarker composition characteristics of oil sand qualitatively and quantitatively. With the number of carbon number increasing, the concentrations of C32-C35 hopane decrease in oil sand, with high content of gamma cerane and no rearranged hopane and rearranged sterane. The distribution of C27--C29 sterane appears in the reverse shape of ＂L＂, with high content of C28 sterane. The sterane isomerization maturity parameter and alkylphenanthrene index indicate that the maturity of oil sand is low. On the basis of comprehensive investigation on the biomarker assemblage characteristics of possible source rocks in this region, we can validate the genesis correlation between oil sand and source rocks in Bayingobi Formation of lower Cretaceous from the characteristics of biomarker fingerprints and their absolute concentrations, h is clear that hydrocarbon source rocks in Bayingobi Formation of lower Cretaceous are the main source rocks of Tiancao sag.

关 键 词：天草凹陷 油源对比 生物标志物组合 定量色谱-质谱 

分 类 号：TE122.113[石油与天然气工程—油气勘探]