摘要
为揭示古老层系过成熟页岩有机质孔隙的发育特征,以上扬子地区下寒武统页岩为例,采用岩石薄片、有机岩石学、有机地球化学、氩离子抛光-扫描电镜等多种技术方法,重点从有机质组成及有机质的赋存方式的角度,开展了有机质孔隙类型的识别,分析了各类孔隙的发育特征及形成机制。研究结果表明:下寒武统页岩主要发育3种有机质孔隙类型:固体沥青内有机质孔隙、有机质-无机矿物复合体内有机质孔隙及莓状黄铁矿集合体内有机质孔隙;页岩固体沥青内有机质孔隙普遍较发育,但孔径小(<30 nm),页岩中天然气大量散失是导致有机质孔隙坍塌萎缩变小的主要原因;有机黏土复合体和莓状黄铁矿集合体形成的稳定抗压结构,有利于有机质孔隙及页岩气的保存。
To reveal the organic matter pore development characteristics of the over-mature shale in the old strata,organic matter pores identification,development characteristics and forming mechanism of pores of Lower Cambrian shale in Upper Yangtze area were studied based on organic components and occurrence manner through thin-sections,organic petrology,organic geochemistry and Ar ion milling/SEM technologies.Results show that organic matter pores in the Lower Cambrian shale consist of three types,i.e.,organic matter pores in the solid bitumen,in the organic matter-inorganic mineral complex and in the strawberry pyrite assemblage.Organic matter pores in the solid bitumen widely occurred but with small pore diameter( < 30 nm),and the expulsion of massive gas was responsible for the collapse and shrinkage of organic matter pores.Organic matter-clay complex and strawberry pyrite assemblage can form stable anti-compression structures,which are favorable for the preservation of organic matter pores and shale gas in them.
作者
刘忠宝
边瑞康
高波
王鹏威
王濡岳
金治光
杜伟
LIU Zhong-bao;BIAN Rui-kang;GAO Bo;WANG Peng-wei;WANG Ru-yue;JIN Zhi-guang;DU Wei(State Key Laboratory of Shale Oil and Gas Enrichment Mechanisms and Effective Development,Beijing 100083,China;Petroleum Exploration and Production Research Institute,SINOPEC,Beijing 100083,China;College of Geosciences,China University of Petroleum(Beijing),Beijing 102249,China)
出处
《世界地质》
CAS
2019年第4期999-1011,共13页
World Geology
基金
国家自然科学基金项目(41872124)
中国石化科技部项目(P15114)
国家科技重大专项(2017ZX05036002001)联合资助
