页岩有机孔研究现状和展望

有机孔是页岩气储层的主要储集空间,也是页岩气储层区别于常规油气储层的重要孔隙类型。目前对有机孔的类型和特征、发育载体及其影响因素等的认识还存在较大争议。系统回顾国内外页岩有机孔的研究现状,调研分析有机孔发育特征及其控制因素,展望有机孔的攻关研究方向,研究认为,页岩的有机质类型是控制有机孔发育的根本因素,矿物类型与组成、成岩作用以及由脆性矿物形成的刚性格架是有机孔形成并保持的重要保障,热演化程度和地层压力对有机孔的发育和保持具有重要的影响。建议加强有机质类型(成烃生物)、不同有机质类型的生烃和排烃模式、矿物类型及其成岩作用(刚性格架形成时间)、页岩生-排烃与矿物成岩作用之间的有机—无机协同演化机制研究,探讨有利的页岩有机孔类型及其发育模式,加强页岩不同尺度储集空间定量表征、有机孔连通性及其影响因素等研究。未来需进一步关注深层—超深层页岩有机孔的发育特征及其保存机制研究。

Research status and prospect on organic matter pores in shale

Organic matter (OM)pores constitute the primary storage space of shale gas reservoirs and are the important pore type that distinguishes shale gas reservoirs from conventional hydrocarbon reservoirs. There are still a lot of controversy about the types and characteristics, development carrier, and influencing factors of OM pores. This paper reviews the research status of OM pores in shale, investigates and analyzes the development characteristics of OM pores and their controlling factors, and looks forwards to the future directions of research on OM pores. The research shows the following results. The OM type of shale is a fundamental factor controlling the development of OM pores; the mineral type and composition, diagenesis and rigid framework formed by brittle minerals play an important role in the formation and maintenance of OM pores; the thermal evolution and formation pressure has important influence on the development and maintenance of OM pores. It is suggested to strengthen the researches on OM types (hydrocarbon-forming organisms), hydrocarbon generation and expulsion of various OM types, mineral types and their diagenesis (formation time of rigid framework), and organic-inorganic co-evolution mechanism between hydrocarbon generation and expulsion of shale and mineral diagenesis. Furthermore, it is necessary to explore favorable OM pore types of shale and their development patterns, to improve the quantitative characterization of shale reservoirs at multiple pore scales, the connectivity of OM pores and its influencing factors, and to enhance the researches on the development characteristics of OM pores and the pore-preserving mechanism in deep and ultra-deep shales.