Logging Evaluation Method For Complex Reservoir Of Pre-Paleogene In X Buried-Hill

The bedrock is an important exploration area for the X buried hill in the M Depression.The petroliferous formation discovered during this period cover the Archean,Proterozoic,Paleozoic,Mesozoic and other Pre-Paleogene strata,and the lithology includes metamorphic rocks,sandstone-shale,volcanic rock,carbonate rock,etc.,and the reservoir types are multiple.Due to the complex lithology and multiple reservoir types of buried hill X,it is difficult to identify lithology and reservoir.Therefore,it is necessary to carry out research on logging evaluation methods of complex reservoirs in the Pre-Paleogene of buried hill X.Based on the logging lithology description,rock section and logging response characteristics,this paper classifies the lithology into different types which can be identified by using logging curves.Based on lithology classification,lithology logging response mechanism analysis,typical lithology logging response characteristics analysis and statistical analysis of lithology logging response are carried out to optimize lithology sensitive logging response.Based on the optimization of lithologic sensitive logging response,the morphological characteristics of lithologic logging curve are studied,the lithologic qualitative identification method is determined,the lithologic identification chart is established,and the comprehensive criterion of lithologic qualitative and quantitative identification is established.The Mesozoic lithology is divided into volcanic rock,breccia and sandstone-shale,and the volcanic rock is mainly andesite,basalt and rhyolite.Five lithology sensitive logging curves are optimized,and three lithology identification charts of volcanic rock are established.The breccia is mainly composed of mixed breccia,basaltic volcanic breccia and granitic breccia.Four lithology sensitive logging curves are selected and two lithology identification charts are established.The sandstone-shale are mainly sandstones and mudstones.Four lithology sensitive logging curves are selected and three lithology identification charts are established.The main lithology of Paleozoic is determined to be limestone,dolomite and mudstone.Five lithology sensitive logging curves are selected and four lithology identification charts are established.The main lithologies of the Proterozoic are quartzite,dolomite and slate.Five lithology sensitive logging curves are optimized and five lithology identification charts are established.The main lithology of the Archean is mixed granite and mixed gneiss.Four lithology sensitive logging curves are selected,three lithology identification charts are established.On the basis of lithology identification,the tppical reservoir is determined by combining the logging oil-bearing display information and oil test data.The logging response mechanism analysis of reservoir space types and response characteristics analysis of typical reservoirs were carried out for typical reservoirs separately by lithology,and the reservoir identification parameters were determined.Using the identified parameters of reservoir identification to establish the reservoir identification chart separately by lithology,and then establish the reservoir qualitative and quantitative comprehensive discrimination standards.The main lithologies of Mesozoic reservoirs are ascertained as andesite,mixed breccia,sandstone and rhyolite.One identification chart of andesite reservoir,two identification charts of mixed breccia reservoir,two identification charts of sandstone reservoir and two identification charts of rhyolite reservoir have been established.The main lithology of Paleozoic reservoir is dolomite and limestone,and a reservoir identification chart is established.The main lithology of the Proterozoic reservoir is dolomite and quartzite,and two reservoir identification charts are established separately by lithology.The main lithology of the Archean reservoir is mixed granite and mixed gneiss,and a reservoir identification chart is established.Based on the production data of oil test,the fluid properties of mixed breccia reservoir are divided by Pickett plot,and the boundary of water saturation of water reservoir and oil-bearing reservoir is given by combining with the conclusion of oil test.Based on core analysis data and conventional logging data,the reservoir parameter interpretation model of shale content,mineral content,matrix porosity,matrix permeability,fracture porosity and fracture permeability is established for the argillaceous carbonate reservoir.In view of igneous rock and metamorphic rock reservoir,the reservoir parameter interpretation models of matrix porosity,matrix permeability,fracture porosity and fracture permeability are established.The saturation parameters of fracture-pore reservoir are calculated by using the connected conductivity model.The logging evaluation method established in this paper is used to process the actual logging data in the study area,and the qualitative and quantitative interpretation results are compared with the corrected lithology and oil test data.The results show that the established interpretation method is suitable for the logging evaluation of the complex reservoir in the pre-Paleogene of X buried hill.