开鲁盆地钱家店凹陷姚家组砂岩中烃类地球化学特征及来源探讨  

GEOCHEMICAL CHARACTERISTICS AND ORIGIN OF INCLUSIONS AND ADSORBED HYDROCARBONS IN YAOJIA FORMATION SANDSTONES IN QIANJIADIAN AREA,THE KAILU BASIN

作　　者：李宏涛 吴世祥[1] 蔡春芳[2] 罗晓容[2] 宝日玛[3] 

机构地区：[1]中国石油化工股份有限公司石油勘探开发研究院,北京100083 [2]中国科学院地质与地球物理研究所,北京100029 [3]中国石油大学,北京102249

出　　处：《石油实验地质》2008年第4期375-381,共7页Petroleum Geology & Experiment

基　　金：国家重点基础研究发展计划(973计划)项目(2003CB214605)

摘　　要：对开鲁盆地钱家店地区下白垩统姚家组砂岩中吸附烃和包裹体烃类进行色谱—质谱测试,分析了它们的地球化学特征,并讨论其可能的来源。吸附烃和包裹体烃生物标志物成熟度参数,C29ααα甾烷20S/(S+R)、C31αβ藿烷22S/(S+R)比值基本达到平衡值,显示含矿砂岩中的烃类已接近成熟—成熟热演化阶段;物质来源及沉积环境参数,ααα20R甾烷百分含量C27>C28<C29,C25/C26三环萜烷、规则甾烷/17αC29-33藿烷比值显示相对低值,结合伽马蜡烷指数、C35升藿烷指数等参数,综合反映了其来源应为弱氧化—还原环境下的腐殖—腐泥型湖相有机质。这些特征与该凹陷侏罗系九佛堂组烃源岩地球化学特征相似,因而,油源可能来自九佛堂组烃源岩。Inclusion hydrocarbons and adsorbed hydrocarbons were observed under microscope and UV fluorescence in Lower Cretaceous Yaojia Formation sandstones in Qianjiadian area, the Kailu Basin. Subsequently, these sandstone samples were washed, crushed, extracted for hydrocarbons and analyzed by GC and GC MS. The results showed that ratios of C-29 ααα sterane 20S / （20S＋20R） and C31 αβ hopane 22S/（22S＋ 22R ）of the hydrocarbons were closed to respective equilibrium values, suggesting that the hydrocarbons were marginally mature to mature. Among C27, C28 and C29 ααα20R steranes, C27〉C28〈C29. Ratios of C25/C26 tricyclic terpane and regular steranes 17αC29-33 hopanes were relatively low. The values together with those of gammacerane index and homohopane index consistently indicated that the inclusion oils and adsorbed hydrocarbons were derived from humic sapropel type organic matter under poor reducing freshwater to semi-saline environment. The features were similar to those of organic matter extracted from the Upper Jurassic Jiufotang Formation source rocks in the Kailu Basin. Thus, it could be concluded that the inclusion oils were mainly derived from the Upper Jurassic Jiufotang Formation source rocks of lacustrine facies.

关 键 词：烃类包裹体 吸附烃 生物标志物 色谱-质谱 钱家店凹陷 开鲁盆地 

分 类 号：TE122.11[石油与天然气工程—油气勘探]