川中地区灯影组四段储层特征及主控因素

Reservoir characteristics and control factors of fourth Member of Dengying Formation in central Sichuan Basin

以钻井资料为基础,采用宏观和微观相结合的方法,分析川中地区灯影组四段储层特征及主控因素。结果表明:该区主要发育台地边缘和局限台地沉积;储集岩石类型主要为颗粒云岩、晶粒云岩和藻云岩;储集空间以溶洞、溶孔为主,裂缝次之,孔隙类型为低孔低渗孔隙-裂缝-溶洞型储层。储层按其成因可分为丘滩相早期岩溶型储层、早期岩溶叠加后期表生岩溶型储层和其他因素改造型储层。研究区储层的发育主要受沉积相、层序界面、成岩作用和构造作用等因素控制。颗粒滩相和藻丘相发育的储层物性好,控制了储层的发育;层序界面控制着储层的分布;岩溶作用是灯四段储层形成的关键,提高了储层的质量;构造运动对储层渗透率的提高具有重要意义。

Based on the drilling data, and the macroscopic and microscopic methods, the reservoir characteristics and control factors of the fourth Member of Dengying Formation in central Sichuan Basin were analyzed. The findings indicate that a range of sedimentary facies developed, such as platform margin facies and restricted platform facies; the reservoir rock includes grain dolomite, crystalline dolomite and algal dolomite; the reservoir space is mainly comprised of karst carve and dissolved pore, the fracture is the second. The pore type is characterized by low porosity and low permeability, belonging to pore-leak-carve reservoir.According to its forming reasons, the reservoir is divided into three categories： the early karst mound-beach reservoir, the earlykarst-overlaid-the-later-supergene karst reservoir and the other factors reservoir. The reservoir development in the study area is controlled by sedimentary facies, sequence interface, diagenesis and tectonism. The good reservoirs developed in the grain beach microfacies and algal mound microfacies that can control reservoir development. The distribution of reservoir is controlled by sequence interface. The most important factor of reservoir forming is the karst, which improves the quality of reservoir; the tectonic movement has important significance to improving the reservoir permeability.