Characteristics Of Lacustrine Carbonate Reservoir In The Yingxi Area,Qaidam Basin

The research area of this project is located in the Western tectonic belt of Yinxiong Ridge in the Qaidam Basin,and the exploration work in the area has made a great breakthrough in recent years,the tectonic form and fault distribution of the area are clarified It is clear that the E32 reservoir is a porous medium lithologic reservoir with tectonic background,it has showed the great potential and prospect of the E32 reservoir are fully demonstrated.However,it is not clear that the characteristics of the deep reservoir in Yingxi,the main types of reservoir space and the control factors of reservoir physical properties,which restricts the further development of deep exploration and exploitation,a lot of detailed data and research results show that:(1)The types of rock in Yingxi area are complex and diverse,and the whole rock analysis shows that it has three major lithology in E32,carbonate rock,gypsum salt rock and clastic rock.The lithology of the deep reservoir in Yingxi is mainly carbonate rock,but there are some differences in the mineral components between salt and salt,and the content of carbonate minerals in salt is higher than that between salt,while the content of Salt Xia Lu Lanxi source clastic,mud and gypsum salt is lower than that of salt.(2)According to the E32 core data,well logging data,in the study of thin slices,Yingxi area includes two types of fractures and pores and five subtypes,including dissolution pore,the second is angular gravel pore,intergranular pore and intergranular pore,and the fracture has double function of seepage storage.The pore type is mainly controlled by deposition and diagenesis,and the fractures are mainly controlled by the late tectonic action.(4)Through the analysis of the physical property of the test sample by the method of nuclear magnetic field and core plunger hole infiltration,the average porosity of the salt reservoir is 6.3%,the average permeability is 0.12mD,the average porosity of salt is 13.1%,the average permeability is 0.98mD,and the whole property is better than that of salt reservoir(3)In the genesis of the reservoir space,the formation of intergranular pores is the quasi-common metasomatism,the dolomite has a minimal pore size,a wide range of porous matrix,and is the most important reservoir space type of the reservoir The cracks are formed by two groups of tectonic joints,which are produced by tensile and compressive stress respectively.A small amount of dissolution pore is the result of a very small amount of organic acids produced by the formation of the mud-crystal dolomite during the geologic-historical period,resulting in the dissolution of the substrate intergranular pores and cracks.