川东地区福成寨构造嘉陵江组二段储层特征

Reservoir Characteristics of 2nd Member of Jialingjiang Formation in Fuchengzhai Structure of East Sichuan

摘要: 以实际钻井岩性资料观察、岩石薄片鉴定分析、物性分析资料为基础，对川东地区福成寨构造嘉陵江组二段储层特征进行了系统研究。研究区嘉二段主要发育灰岩、白云岩和膏岩类，但储集岩类主要为晶粒白云岩和颗粒白云岩。结合铸体薄片和扫描电镜分析，嘉二段储集空间以粒间孔、晶间孔、晶间溶孔和裂缝为主。物性分析结果表明嘉二段储集性能总体较差，属于裂缝–孔隙型和孔隙–裂缝型储层。储层段主要分布于嘉二2亚段，嘉二1亚段次之，嘉二3亚段相对最差。嘉二段储层主要受控于岩石类型、沉积相带分布、成岩作用类型及构造作用等，其中粒屑滩和云坪微相为有利储集相带，溶蚀作用和白云石化作用为有利储层形成的成岩作用，构造作用形成大量的微裂缝有利于提供储层的渗透性及高质量储层的形成。

Abstract: Based on the core description, thin sections identification, and physical property data analysis, reservoir char- acteristics of 2nd member of Jialingjiang Formation in Fuchengzhai area, eastern Sichuan, are studied in detail. The results show that the rock types of T1j2 are limestone, dolostone and cream rock, and reservoir rocks are mainly crystal- line dolostone and grain dolostone. The combination analysis of casting thin sections and scanning electron microscopy shows that reservoir space mainly exists in secondary pores (inter-grain pore, intercrystal pore, inter-crystal dissolved pore) and fractures. The mass-properties analysis indicates that the reservoir property of T1j2 is poor, which belongs to fracture-pore and pore-fracture reservoir. Favourable reservoirs are mainly developed in T1j22, less in T1j21, and least in T1j23. Moreover, the reservoirs of T1j2 are mainly controlled by rock types, distributions of sedimentary facies, diagene- sis forms, tectonic actions, and so on, among which bank and tidal flat of dolomite are favourable reservoir facies, dis- solution and dolomization contribute to diagenesis, and microfractures shaped in tectonic activity are conducive to form the high quality reservoir and develop its permeability.