Research On Reservoir Characteristic Of The Tenggeer Formation In Daerqi Area Of Baiyinchagan Depression

The paper has studied on the reservoir characteristics of Tenggeer formation of Daerqi area in Baiyinchagan Depression using well-logging,core,thin section and analysis assay data.In the end,we acquired the following major awareness.The lithic sandstone and the quartz lithic sandstone are the main rock types in Tenggeer formation.Both in the D34 wellblock of the southwestern area and in the D14 wellblock of the southeastern area,the content of quartz is high,and that of lithic is high;however in the D1 wellblock of the north area,quartz are rich in the content.According to the amount of different lithic type of the reservoir sandstone in Tenggeer Formation,there are metamorphic rock,sedimentary rock and magmatic rock from large to small.In the D34 wellblock of the southwestern area,sedimentary rock debris is the most one,however,in the D14 wellblock of the southeastern area,that is metamorphic rock debris.There are two main types of rock fragment in the D1 wellblock of the southwestern area,respectively metamorphic rock debris and sedimentary rock debris.The reservoir of Tenggeer formation is determined in the middle of diagenesis A stage.The type of diagenesis is diverse,including compaction,cementation,metasomatism,dissolution.On the whole,the intensity of compaction is medium,which is related to the grain,the deeply buried fine grain is tightly compacte;the level of cementation is weak.In the study area,there are three pore types,which refer to primary inter-granular pores,dissolved intra-granular pores and fissures.There are three capillary pressure curve,the type of II is common,which explain the reservoir is characterized by medium porosity and permeability.Combined with the previous research and based on the lithology,diagenesis,pore type,physical property,pore throat,we establish the criterion to classify the reservoir of Tenggeer formation in Daerqi area,find that there are three different reservoir types.what's more,we evaluate reservoir for the important wells and region.the reservoir of the Upper Tenggeer formation is characterized by the type of II,that of the Lower Tenggeer formation is characterized by the the type of III.