Study On Sedimentary Facies And Reservoir Characteristics Of Shanxi Formation In Jin66-Jin72 Well Area,Hangjinqi

On the basis of many previous studies,this paper takes Shanxi formation in Jin66-Jin72 well area of Hangjinqi area in Ordos Basin as the research object.Through the knowledge of sedimentary geology,petrographic paleogeography and reservoir sedimentology,combined with logging and test analysis data,the characteristics of sedimentary microfacies,the distribution of sedimentary microfacies and reservoir characteristics in the study area are systematically studied from macro and micro aspects.(1)Making full use of the exploration wells and development wells of Shanxi formation,the Shanxi formation in the study area is divided into Shan1 and Shan2 members,and on this basis,four small strat a are divided,and the Shan1 member is divided into two small strata(S1-1,S1-2).The mountain 2 member is divided into two small layers(S2-1,S2-2).(2)Through drilling core observation,all kinds of test analysis and comprehensive analysis of logging data,through the identification marks of rock color,lithology,sedimentary structure and profile structure of Shanxi formation in the study area,the Shanxi formation in the study area is divided into delta deposits,which are further divided into five microphases: shunt channel,natural embankment,crevasse fan,shunt depression and peat swampy,and the development characteristics of various sedimentary microfacies are systematically studied.(3)The thickness and dominant phase of each small layer sand body of Shanxi formation in the study area are counted,and the thickness map of each small layer sand body is compiled.Combined with the dominant phase of single well,the plane distribution characteristics of sedimentary microfacies in four small layers of Shanxi formation are systematically studied.The direction of provenance comes from the north,and the main body on the plane is the microphase of the shunt channel,and there are differences in the development position and scale of the vertical shunt channel.(4)Through the observation of ordinary thin sheet,casting sheet and scanning electron microscope,the reservoir development characteristics of Shanxi formation in the study area were studied.The Shanxi formation is mainly coarse to medium grain sandstone,medium to fine grain sandstone,the rock types include quartz sandstone,lithic quartz sandstone and lithic sandstone,and the reservoir pore types are mainly intergrain pores and intragranular dissolved pores.According to the characteristics of porosity and permeability correlation,Shanxi formation reservoirs have typical low porosity,low permeability characteristics,mainly pore type reservoirs.Reservoir sandstone of Shanxi formation has experienced many diagenetic processes,including compaction,cementation,metasomatism and alteration,and dissolution.