内蒙古西部额济纳旗及邻区二叠系埋汗哈达组烃源岩生物标志化合物的特征及意义  

Biomarker characteristics of Permian Maihanhada Formation hydrocarbon source rocks in Ejin Banner and its vicinities,western Inner Mongolia,and their significance

作　　者：魏建设[1] 卢进才[1] 陈高潮[1] 李金超[1] 

机构地区：[1]中国地质调查局西安地质调查中心,陕西西安710054

出　　处：《地质通报》2011年第6期904-910,共7页Geological Bulletin of China

基　　金：中国地质调查局国土资源大调查项目<西北地区中小盆地群油气资源远景调查>(编号:1212010733506)

摘　　要：通过对正构烷烃、类异戊二烯烷烃、萜烷、甾烷等生物标志化合物的研究,对额济纳旗及其邻区二叠系埋汗哈达组的沉积环境、烃源岩干酪根类型、成熟度等进行了评价。烃源岩Pr/Ph绝大部分小于1,显示植烷优势,表明研究区二叠系埋汗哈达组沉积环境为还原—强还原环境,有利于有机质的富集,物源来自于陆源高等植物和水生生物,且以水生生物输入占优势;利用Pr/nC17-Ph/nC18、C27-C28-C29甾烷等生物标志化合物的关系评价区内埋汗哈达组烃源岩有机质类型以Ⅱ2型为主;对OEP、萜烷、C29甾烷等参数分析表明,额济纳旗及其邻区二叠系埋汗哈达组烃源岩处于成熟—高成熟阶段,有利于油气的生成。The accuracy of the surface outcrop hydrocarbon source rock evaluation result by using the traditional method is doubtful in the lower exploration degree area.Based on a study of such biomarkers as n-alkanes,isoprenoid alkenes,terpane and sterane,the authors evaluated the sedimentary environment,source rock kerogen type and maturity of Permian Maihanhada Formation in Ejin Banner and its vicinities.Pr/Ph ratios of most source rocks are lower than 1,and the phytane advantage is distinct,which shows that sedimentation of Permian Maihanhada Formation occurred in a reducing-highly reducing environment,which was beneficial for organic concentration,and the provenance was terrigenous higher plants and aquatic organisms,with the obvious input advantage of aquatic organisms.The relationship between Pr/nC17-Ph/nC18 and C27-C28-C29 sterane shows that the kerogen of Maihanhada Formation source rocks was mainly of the Ⅱ2 type.The parameters of OEP,terpane and C29 sterane show that the source rock of Permian Maihanhada Formation was mature-highly mature in Ejin Banner and its vicinities,which was beneficial for hydrocarbon generation.

关 键 词：额济纳旗及其邻区 二叠系埋汗哈达组 烃源岩 生物标志化合物 

分 类 号：P534.46[天文地球—古生物学与地层学] P618.13[天文地球—地质学]