川东南地区飞仙关组碳酸盐岩储层特征

Characteristics of carbonate rock reservoir of Feixianguan Formation in southeastern Sichuan Basin

徐胜林 2 陈洪德 林良彪 2 陈安清

1．成都理工大学油气藏地质及开发工程国家重点实验室，四川 成都 610059 2．成都理工大学沉积地质研究院，四川 成都 610059

State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Chengdu University of Technology, Chengdu 610059, China Institute of Sedimentary Geology, Chengdu University of Technology, Chengdu 610059, China

在野外剖面、钻井岩心详细观察的基础上，通过对染色薄片、岩石薄片、扫描电镜和物性等资料的综合分析，对川东南地区下三叠统飞仙关组碳酸盐岩储层特征的研究结果表明，储集层岩石类型主要为鲕粒灰岩、泥晶灰岩和少量的白云岩，其中最佳储集体鲕粒灰岩主要发育于飞仙关组三段；储集层储集空间以次生孔隙为主，主要发育晶间孔、晶间溶孔、粒间溶孔和粒内溶孔4种类型；储集层物性较差，为低孔隙度、低渗透率的储集层。研究认为沉积相、成岩作用和构造运动对储集层具有明显的影响，其中沉积相类型控制了储集层发育位置，而成岩作用和构造运动则对储集层物性具有控制性的影响。白云石化作用和压溶作用较好的改善了储层的孔渗情况，胶结作用和压实作用则对储层孔渗起到破坏性作用，导致了储层的孔渗能力变差；构造运动则总体上体现为改良研究区飞仙关组储层的孔渗能力。

Based on observation of outcrops, cores, through integrated investigation such as stained rock thin section microscopic identification，scanning electron microscope, porosity and permeability analysis and so on, the characteristics of the carbonate rock reservoir  in the southeastern Sichuan Basin are studied. The results show that reservoir rocks are dominated by oolith limestone, micrite and dolomite, and the best reservoir oolith limestone is mainly developed within Member 3 of Feixianguan Formation. The main pore types of the reservoir in the studying area are secondary porosity of intercrystal pore, intercrystal dissolved pore, intergranular pore and intergranular dissolved pore. The reservoir physical properties are poor, that is to say, the studied area is a dense reservoir with low porosity and low permeability. Depositional facies, digenesis and tectonic movement are the main factors which influence the character of reservoir. The location of the reservoir is controlled by the depositional facies, and the reservoir physical properties are mainly controlled by digenesis and tectonic movement. Dolomitization and pressure solution improve the physical properties and pores of reservoir significantly. But cementation and compaction play destructive roles to physical properties and pores of reservoir, which causes poor capability of porosity and permeability. In all, the influence of tectonic movement to the reservoir is the same to the dolomitization and pressure solution, which could improve the reservoir quality.