塔河油田三叠系原油有机地球化学特征及成因  

Organic geochemical characteristics and genesis of crude oils of triassic Tahe oilfield

作　　者：郑朝阳[1] 于文修[2] 段毅[3] 柳益群[1] 

机构地区：[1]西北大学地质系,大陆动力学国家重点实验室,西安710069 [2]中国石化勘探开发研究院无锡实验地质研究所,江苏无锡214151 [3]中国科学院兰州地质研究所,兰州730000

出　　处：《兰州大学学报（自然科学版）》2010年第6期34-40,共7页Journal of Lanzhou University(Natural Sciences)

基　　金：国家重点基础研究发展计划(973计划)项目(2005CB422105);中国石化海相前瞻项目(YPH08103)

摘　　要：通过系统采样和精细的GC-MS分析,研究了塔河油田三叠系原油有机地球化学特征及成因.研究结果表明:原油(w(Pr))/(w(Ph))相对较低,(w(pr))/(w(nC_(17)))和(w(Ph))/(w(nC_(18)))相关图反映其形成于还原环境,含有相对丰富的γ-蜡烷和>C_(30)藿烷,说明原油形成于海相咸水环境;原油中含有较丰富的C_(27)甾烷、三环萜、四环萜和较高的三环萜烷/藿烷,指示其母质来源为菌藻类;原油中高丰度的重排甾烷,较高的(w(Ts))/(w(Ts+Tm))和(w(C_(29)ββ))/(w(ββ+αα))说明原油具有较高的成熟度,为成熟原油;25-降藿烷的检出说明原油受到一定的生物降解,加之完整的正构烷烃分布以及研究区油气地质条件推断存在至少两次油气充注过程.Biomarkers and their genesis were studied.The data of（w（Pr））/（w（Ph））,（w（Pr））/（w（nC_（17））） and（w（Ph））/（w（nC_（18））） indicated that oils formed from sapropel organic matters of reducing environment.Abundance of gammaceraneC_（30） hopane indicated that the oils formed from saltwater environment.The abundance of C_（27） sterane,tricyclic terpane,tetracyclic terpane and higher tricyclic terpane/hopane parameters showed that original source materials were homonemeaes.The abundance of rearranged sterane was higher and higher（w（Ts））/（w（Ts＋Tm）） and （w（C_（29）ββ））/（w（ββ＋αα）） sterane showed that the maturity of the oils was higher.The detection of 25-norhopane indicated that the oils met with biodegradation and,together with integral distribution of n-alkane,it showed that oil pool underwent no less than two oil accumulating processes.

关 键 词：三叠系 原油 成熟度 重排甾烷 生物降解 

分 类 号：TE122[石油与天然气工程—油气勘探]