Paleoenvironmental reconstruction and organic matter accumulation of the paleogene shahejie oil shale in the Zhanhua Sag, Bohai Bay Basin, Eastern China  

作　　者：Xiao-Lin Wang Xiao-Min Zhu Jin Lai Xing-Yue Lin Xiang Wang Yu-Shan Du Chao Huang Yu-Rui Zhu 

机构地区：[1]State Key Laboratory of Petroleum Resources and Engineering,China University of Petroleum(Beijing),Beijing,102249,China [2]College of Geosciences,China University of Petroleum(Beijing),Beijing,102249,China [3]Shengli Oilfield,SINOPEC,Dongying,257000,Shandong,China

出　　处：《Petroleum Science》2024年第3期1552-1568,共17页石油科学（英文版）

基　　金：supported by the National Natural Science Foundation of China(No.42272110)。

摘　　要：The controlling factors of organic-rich shale accumulation is essential for the exploration and development of shale oil and gas resources.The sedimentary environment plays a vital role in the formation of organic-rich sediments in lacustrine facies.This article unravels the mineralogy,geochemistry,and paleoenvironmental evolution during the deposition of the Paleogene Shahejie Formation(Es_(3)^(L)).It discusses the effects of paleoclimate,paleosalinity,paleoredox conditions,paleowater depth,and paleoproductivity on organic matter(OM)enrichment.Finally,the OM enrichment model was established.The results show that the mineralogical compositions are mainly composed of calcite(avg.40.13%),quartz(avg.21.64%)and clay minerals(avg.24.07%),accompanied by dolomite(avg.7.07%),feldspar(avg.6.36%)and pyrite(avg.2.95%).The Es_(3)^(L) shale has a high abundance of OM,with total organic carbon(TOC)ranging from 1.07%to 5.12%.The organic matter type is mainly composed of type I-II_(1) kerogen,which is generally considered a good-quality source rock.The source of OM is a mixture of lower bacteria,algae,and plants.During the early sedimentary period,the paleoclimate was dry and cold,with high salinity,intense reducibility,and relatively low productivity.During the late sedimentary period,the climate became warmer and more humid.As a result,the salinity decreased to a level that was suitable for biological reproduction,and productivity increased gradually due to the input of terrigenous plants.Paleosalinity and paleoclimate determined the environment of the sedimentary period,in addition,paleoproductivity and paleoredox condition indicated the formation and preservation conditions of OM.The warm and humid climate,brackish water,suitable reduction conditions and high productivity are the favorable conditions for the generation and preservation of organic matter.The research results may have implications for the genetic mechanisms of organic matter accumulation.They will provide theoretical and technical insights into the exploration

关 键 词：Elemental geochemical PALEOENVIRONMENT Organic matter accumulation Paleogene shahejie formation Zhanhua Sag Bohai Bay Basin 

分 类 号：P618.13[天文地球—矿床学]