柴西南七个泉油田原油地球化学特征研究  

Study on Geochemistry Characteristics of Crude Oil from Qigequan Oilfield in Southwest Qaidam Basin

作　　者：李建明[1,2] 史玲玲[2] 王华[1] 张道伟[3] 张敏[3] 

机构地区：[1]中国地质大学湖北省油气勘探开发理论与技术重点实验室,湖北武汉430074 [2]长江大学地球科学学院,湖北荆州434023 [3]中石油青海油田分公司勘探开发研究院,甘肃敦煌736202

出　　处：《石油天然气学报》2011年第1期17-20,52,共5页Journal of Oil and Gas Technology

基　　金：湖北省油气勘探开发理论与技术重点实验室开放研究课题基金项目(96005)

摘　　要：通过对柴达木盆地西部南区七个泉油田2口油井原油样品生物标志物特征的系统分析表明:七个泉油田正构烷烃分布完整,主峰碳为C22,CPI<1,呈偶碳优势,Pr/Ph低,反映其母质源岩来自强还原环境。双环倍半萜系列组成中补身烷和升补身烷含量高。规则甾烷组成以C27>C29>C28为特征,呈"L"型,生油母质以低等水生生物为主,油样中还存在重排甾烷和4-甲基甾烷;萜烷系列中藿烷系列分布完整,C30藿烷为主峰,C35/C34藿烷值为1.66和1.67,伽马蜡烷丰度极高,其伽马蜡烷/C30藿烷值为1.18和1.29。原油成熟度参数C29甾烷ααα20S/(20S+20R)、αβ/β(αββ+ααα)及Ts/Tm都说明原油未成熟,碳同位素值较重。经过与柴北原油、柴西烃源岩对比证实,七个泉油田与西部第三系咸水湖相原油特征更为接近,主要为强还原、高盐度沉积环境。Through systematic analysis on composition of various biomarkers of oil samples from 2 wells in Qigequan Oilfield,the study indicated that the crude oil in the Qigequan Oilfield had the integrated normal paraffin hydrocarbons,the dominant peak carbon is C 22,CPI was less than 1,even odd-to-even carbon was predominance and low ratio of Pr/ Ph,so all the characteristics reflected the parent source rock was derived from strong reducing environment.In the composition of dicyclic sesquiterpenoids,it had higher drimane and ascended driman.The feature of composition of regular sterane was C 27>C 29>C 28,and it presented L pattern,which illustrated that the original source material was derived from lower aquatic organism.What is more,it contained rearranged sterane and 4-methylsteranes.In the serial of terpane,it had integrated dist ribution of hopane serial and the main hopane is C 30.The ratio of C 35 /C 34 is between 1.66 to 1.67,in gammacerane /C 30 hopane ,it was 1.18 to 1.29 and the gammacerane was of great abundance.The low ratios of C 29 sterane 20S/(20S+20R),αββ/(αββ+ααα) and Ts/Tm show that the crude oil is immature.Carbon isotopic compositions is partially heavy.After comparison of crude oils from the west and north of Qaidam Basin,the characteristics of crude oils in Qigequan Oilfield are similar to Tertiary saline lacustrine oil in the western Qaidam Basin,and it is mainly the product from the higher salinity and stronger reducing environments.

关 键 词：地球化学特征 生物标志物 碳同位素 七个泉油田 柴达木盆地 

分 类 号：P618.13[天文地球—矿床学]