Identification and geochemical significance of unusual C24 tetracyclic terpanes in Shahejie Formation source rocks in the Bozhong subbasin,Bohai Bay Basin  

作　　者：Ning Wang Yao-Hui Xu Fei-Long Wang Yan Liu Qian Huang Xing Huang 

机构地区：[1]Key Laboratory of Exploration Technologies for Oil and Gas Resources,Ministry of Education,Yangtze University,Wuhan,430100,China [2]Hubei Key Laboratory of Petroleum Geochemistry and Environment(Yangtze University),Wuhan,430100,China [3]Bohai Petroleum Research Institute,Tianjin Branch,CNOOC(China)Ltd.,Tianjin,300452,China

出　　处：《Petroleum Science》2022年第5期1993-2003,共11页石油科学（英文版）

基　　金：supported by open fund of Key Laboratory of Exploration Technologies for Oil and Gas Resources(Yangtze University),Ministry of Education,No.K2021-13;China Postdoctoral Science Foundation(2021M692751);Tianjin branch of CNOOC(CCL2020TJT0NST1956)。

摘　　要：C_(24)tetracyclic terpanes are common compounds in source rocks and crude oils,and C_(24)17,21-secohopane is the most common and widely used source-related indicator.In this study,three unusual C_(24)tetracyclic terpanes were detected on the m/z 191 chromatogram of saturated hydrocarbons in the Shahejie Formation source rocks in the Bozhong subbasin.Based on the mass spectra characteristics,diagnostic ion fragments,retention time and comparisons with published literature,three unusual C_(24)tetracyclic terpanes were identified as 10β(H)-des-A-oleanane,10β(H)-des-A-lupane and C_(24)des-Ahopane.To the best of our knowledge,this is the first study to detect and publicly report these three compounds in source rock samples from the Shahejie Formation of the Bozhong subbasin,Bohai Bay Basin.The results indicated that 10β(H)-des-A-oleanane and 10β(H)-des-A-lupane likely originated from terre strial angiosperms,while C_(24)des-A-hopane likely originated fro m prokaryotic o rganisms.Te rrestrial angiosperms provide the material basis for the generation of compounds A and B,and the distribution and concentration of these two compounds are affected by thermal maturity.In the low maturity stage(0.5%<R_(0)<0.7%),compounds A and B are relatively enriched in the source rocks.

关 键 词：Unusual tetracyclic terpanes 10β(H)-des-A-oleanane 10β(H)-des-A-lupane Geochemical significance Shahejie Formation Bozhong subbasin 

分 类 号：P618.13[天文地球—矿床学]