藏北羌塘盆地井下布曲组含油白云岩地球化学特征及其意义  

Geochemical features of oil-bearing samples from the well in Buqu Formation in the Qiangtang Basin,northern Tibet,and their implications

作　　者：王忠伟[1,2,3] 王剑[3] 付修根[3] 陈文彬[3] 卫红伟[3] 宋春彦[3] WANG Zhongwei;WANG Jian;FU Xiugen;CHEN Wenbin;WEI Hongwei;SONG Chunyan(School of Earth Sciences, China University of Geosciences, Wuhan 430074, Hubei, China;Chinese Academy of Geological Sciences, Beijing 100037, China;Sedimentary Geology Research, Chengdu Center of China Geological Survey, Chengdu 610081, Sichuan, China)

机构地区：[1]中国地质大学(武汉)地球科学学院,湖北武汉430074 [2]中国地质科学院,北京100037 [3]中国地质调查局成都地质调查中心沉积地质研究室,四川成都610081

出　　处：《地质通报》2017年第4期591-600,共10页Geological Bulletin of China

基　　金：国家自然科学基金项目<羌塘盆地海相油页岩:沉积环境;古气候及源区>(批准号:41172098);中国地质调查局项目<羌塘盆地金星湖-隆鄂尼地区油气资源调查>(编号:DD20160159)

摘　　要：羌资11、12井是羌塘盆地揭示隆鄂尼-昂达尔错古油藏展布规律的资料井。对这2口钻井揭示的含油岩层进行取样分析,结合前人该区石油地质调查报告中羌资2井布曲组、夏里组及曲色组烃源岩的分析数据,从类异戊二烯烃、甾烷、萜烷等系列生物标志化合物参数方面进行油-岩对比研究。研究表明,羌资11、12井揭示的原油为同一种类型,但11井原油生物降解程度强于12井。各原油的母质主要来源于低等水生生物和藻类;各原油的母质形成于还原-弱还原、盐度值不高的咸水环境。原油中类异戊二烯烃、萜烷、甾烷等生物标志化合物参数与羌资2井布曲组泥晶灰岩与夏里组和曲色组烃源岩之间具有较好的亲缘性。结合南羌塘地区烃源岩有机碳资料,油源可能主要来自于曲色组,混入了部分夏里组及布曲组的油源,具有混源的特征。该研究结果对下一步油气勘探具有一定的指导意义。The Qiangzi-11and12wells are the data well to reveal the distribution regularities of Longeni-Angdaerco palaeo-oil reservoirs.Together with the hydrocarbon source rock data of Buqu Formation,Xiali Formation,and Quse Formation from Qiangzi-2well,the authors analyzed the oil-rock correlations based on the biomarker parameters composed of isoprenoid,steranes,and ter?panes.The property of crude oil from Qiangzi-11and12wells is of the same type.However,the biodegradation degree from Qiang?zi-11well is higher than that from Qiangzi-12.The biomarker parameters reveal that the organic matter mainly originated from algae.The crude oil was formed under weak reduction-reduction conditions and in a slightly salty water environment.The biomarkersof crude oil,composed of isoprenoid,terpane,and sterane,are closely related to those of the Buqu Formation in Qiangzi-2well,andalso show good correlation with those of the Xiali Formation and Quse Formation in Qiangzi-2well.Combined with the TOC data of the hydrocarbon source rock in south Qiangtang Basin,the authors hold that the crude oil of the Longeni-Angdaerco palaeo-oilreservoir was mainly from the source rocks of Quse Formation,and partly from the Xiali and Buqu Formations,suggesting a mixture of sources.The result of this study may have some guidance significance for further oil-gas exploration.

关 键 词：生物标志化合物 含油白云岩 布曲组 油-岩对比 羌塘盆地 

分 类 号：P618.13[天文地球—矿床学]