Logging Identification And Application Of Mixed Carbonate Reservoir Lithology And Lithofacies Of The Lower Ganchaigou Formation In Yingxi Area

In recent years,the mixed carbonate reservoirs in the upper member of the Lower Ganchaigou Formation in Yingxi area of the western Qaidam Basin have made major breakthroughs,but the lithology is complex,and the mineral components include carbonate components and terrigenous debris.gypsum,salt rock and argillaceous make it difficult to identify the lithology and lithofacies of mixed carbonate reservoir.In this paper,the core data,thin section analysis,conventional logging,imaging logging and lithologic scanning logging are fully utilized to analyze the lithologic and lithofacies characteristics of the mixed carbonate reservoir in the target stratum,and further summarize them.The composition,structure and sedimentary facies are divided into speckle limestonedolomite facies,weakly stratified muddy limestone-dolomite facies,Strong stratified shaly limestone-dolomite facies and massive lime/dolomitic mudstone facies.And establish logging identification criteria for karst facies of mixed carbonate rocks.Analysis of the relationship between lithology and lithofacies and reservoir quality.The results show that lithology and lithofacies have a controlling effect on reservoir porosity and brittle exponential.The reservoir quality of speckle limestone-dolomite facies and weakly stratified muddy limestone-dolomite facies is better.The study of mixed carbonate lithology and lithofacies provides theoretical guidance for reservoir comprehensive evaluation and favorable zone prediction in Yingxi area.