Study Of Reservoir Heterogeneity Of Chang 8 Reservoir In Maling Region

Maling Oilfield is located in southwest Ordos Basin.Chang 8 group is a set of delta front facies of terrigenous clastic sediments which develop argillaceous sandstone and mid-fine grained sandstone,forming a set of low porosity and low permeability,extra-low permeability reservoir group.Guiding by methods and theories of sedimentary petrology,logging geology,reservoir geology geological background of the study area is analysed,Chang 8 reservoir is divided into chang 81 and chang 82.And Chang 81 oil-bearing formation,which is selected as the main research object,is divided into chang 811,chang 812 and chang 813.Through analysis of the core and logging data,combined with the test technology such as core description and electron the microscope analysis,the characteristics of reservoir is described,and the reservoir flow units is divided on the basis of research of reservoir heterogeneity.In this paper,the study shows that in-layer heterogeneity is powerful,interlayer heterogeneity and planar heterogeneity are severe,the difference for change of porosity is obvious,micro heterogeneity is also strong.This was mainly due to Sedimentation and diagenesis.Based on those results,according to the core property data,the classification standard of Chang 81 reservoir flow units is confirmed by using the FZI method.The result is that Chang 81 reservoir can be grouped into 4 types of flow units,the reservoir property of flow unit ? is the best,and that of flow unit ? is the worst.Chang 81 reservoir are mainly of type ? and ? flow units.According to distribution of flow units,flow unit ? has a good reservoir property,while the distribution of area is small.Therefore,the distribution of flow unit ?,which has larger areas and higher porosity and permeability,will be the next major exploration zone.Those results can provide geological theoretical basis for further development.