马朗凹陷芦草沟组页岩油储层成岩演化与溶蚀孔隙形成机制  

Diagenetic evolution and formation mechanism of dissolved pore of shale oil reservoirs of Lucaogou formation in Malang sag

作　　者：吴林钢[1] 李秀生[1] 郭小波[2] 罗权生 刘晓健[2] 陈旋 姜振学[2] 

机构地区：[1]中国石油大学石油工程学院,北京102249 [2]中国石油大学地球科学学院,北京102249 [3]中国石油吐哈油田勘探开发研究院,新疆哈密839009

出　　处：《中国石油大学学报（自然科学版）》2012年第3期38-43,53,共7页Journal of China University of Petroleum(Edition of Natural Science)

基　　金：国家'973'重点基础研究发展规划项目(2011CB201105)

摘　　要：通过场发射环境扫描电子显微镜、X射线衍射等试验手段,对三塘湖盆地马朗凹陷芦草沟组页岩油储层成岩演化特征与溶蚀孔隙形成机制进行研究。结果表明:二叠系芦草沟组泥页岩为低孔、特低渗储层,主要经历了压实、胶结、交代以及溶解等成岩作用;有机质热演化与无机矿物成岩演化在时空上相对应,有机质生烃高峰、孔隙度高值区、伊利石含量高值区在同一深度出现;生烃过程形成的酸性流体溶解不稳定矿物,形成溶蚀孔隙,同时为伊利石化提供K+;矿物溶蚀孔和有机质残留孔是页岩油重要的储集空间,伊利石化可加速钾长石溶解,并造成矿物的体积收缩,对储集空间的形成具有明显促进作用;泥页岩中溶蚀孔隙的形成与有机质生烃、油气初次运移同步。Based on the analysis of field emission ESEM, X-ray diffraction, the characteristics of diagenetic evolution and the formation mechanism of dissolved pores of Lucaogou formation shale oil reservoir in Malang sag were systematically researched. The results show that Permian Lucaogou formation shale oil reservoir is characterized by low porosity and uhralow-permeability. The reservoir mainly experienced compaction, dissolution, cementation and metasomatism. Organic matter and inorganic miner- al diagenetic evolution are corresponding at space and time, because peak period of hydrocarbon-generating, high porosity and high illite content occur at the same depth. The acid fluid generated by hydrocarbon formation can dissolve unstable minerals and therefore form dissolved pores, which provides K^＋ for illitization at the same time. Dissolved pores and organic-matter pores are the major storage spaces of shale oil. Illitization accelerates the dissolution of potassium feldspar and causes mineral volume contraction, which obviously promotes the formation of secondary pores. The progress of the formation of dissolved pores is synchronized with hydrocarbon generation and the primary migration of oil.

关 键 词：页岩油 储层 成岩演化 溶蚀孔隙 形成机制 马朗凹陷 

分 类 号：TE122.2[石油与天然气工程—油气勘探]