四川盆地灯影组储层特征及主控因素

摘要

Dengying Formation of Sinian is one of the most important gas-bearing strata in Precambrian of China.Based on the lithology characteristics,the scanning electron microscope,the cathode luminescence and some other experimental analyses,this paper studies some samples taken from the outcrops and the drilling cores of Dengying Formation in Sichuan Basin.This paper studies the dolomite reservoir of Dengying Formation.The types of the dolomite reservoir are mainly the algal stromatolite dolomite,algal lamellar dolomite,algal dolarenite,algal oncolite dolomite and algal grumous dolomite,and so on.There are altogether 6 kinds of reservoir pore spaces in Dengying Formation.Among them,the interbreccia pores,the mass dissolved pores-caves and the “grape-lace”remnant pores-caves are very important.The Development of the dolomite reservoir is mainly controlled by sedimentary facies,dolomitization,dissolution,sea level ecstasy and tectonic action. The sedimentary facies is the environment basement of the reservoir.The dolomization is the key that the reservoir can be preserved.The dissolution,sea level eustasy and tectonic action are the key factors to make pore spaces.The tectonic fracture is an important factor to improve the reservoir.The cementation and silicification will fill the pores and are destructive factors for the reservoir in Dengying Formation.%灯影组是前寒武纪最重要的含气层系之一。以钻井岩心及露头剖面样品的镜下岩石学特征为基础，以阴极发光、扫描电镜等实验方法为辅助手段，对四川盆地灯影组白云岩储层进行了研究。认为灯影组白云岩储层类型主要为藻叠层白云岩、藻纹层白云岩、藻砂屑白云岩、藻核形石白云岩、藻凝块白云岩等。储集空间被分为6类，其中砾间孔、大规模溶孔溶洞以及“葡萄花边”残留孔洞是灯影组最主要的储集空间。四川盆地灯影组形成储层的控制因素有：沉积相带、白云石化作用、表生喀斯特作用、构造作用以及海平面升降变化等。其中沉积相带是灯影组储层形成的物质环境基础，白云石化作用是储层得以保存的必要条件；表生喀斯特作用、构造作用、海平面升降等因素是储层形成的关键因素，构造裂缝是储层改善的重要条件；而胶结作用和硅化作用则是灯影组储层受到破坏的重要因素。