Study On The Characteristics Of Chang 6 Reservoirs In Ma Digou Area Of Ordos Basin

Based on previous studies and guided by the theories of sedimentary stratigraphy,reservoir geology,reservoir petrology,petroleum geology geophysics and so on,this paper analyzes the data of core observation photos,sheet identification reports,cathodoluminescence analysis reports,scanning electron microscope reports,mercury pressure test data,nuclear magnetic resonance,sensitivity identification reports,etc,combines with basic map data and regional sedimentary background data,studies the characteristics of stratigraphic development,sedimentary facies,reservoir petrology,pore structure and reservoir heterogeneity of the Chang 6 oil group of Yanchang Formation in Ma Digou area,through the research,the following insights are:The sedimentary environment of Yanchang Group 6₁ in Madigou area is delta plain sedimentary environment,which mainly develops distributary channel and interchannel sedimentary microfacies;The Chang 6₁ reservoir is mainly feldspar sandstone,and the cementation is dominated by chlorite,hydromica and iron calcite.The pore types of reservoir are mainly intergranular pore and feldspar pore,followed by intergranular pore,but also contain a small amount of cuttings pore,mold hole and so on.The pore assemblage is intergranular pore-soluble pore,and the pore-throat assemblages are mainly small pore-fine throat and fine pore-fine throat.;The physical property data show that the Chang6₁ reservoir in Ma Digou area belongs to low porosity and ultra-low permeability reservoir;The heterogeneity of Chang 6₁ reservoir in Ma Digou area is as follows:the heterogeneity of Chang 6₁² stratum is weaker than that of Chang 6₁¹ and Chang 6₁³ stratum;The Chang6₁Reservoir Formation in Madi Gou area is in A period of mudstone,its reservoir sensitivity was characterized by weak alkali sensitivity,weak water sensitivity,moderate weak salt sensitivity and weak speed sensitivity,and there are 4 types of reservoirs developed in the study area,of which class III reservoirs are most widely distributed.