Research On The Plane Distribution And Reservoir Characteristics Of The Ordovician Sedimentary Facies In East Lungu

In this paper,the study area is mainly in the area of eastern lungu.The formation of Ordovician was devied into:penglaiba Formation,Yingshan ormation,Yij ianfang Formation,Tumuxiuke Formation,Lianglitage Formation,Sangtamu Formation in the area of Lungu.According to drilling and well logging anf seismic data,combined with paleontology,lithology and the rule of sea-level fluctuation change,through stratigraphic division and correlation,we think that the Tumuxiuke Formation of Ordovician is regional correlation marker in the study area.Due to the differences of the Denudation extent,Lianglitage Formation in the group changes slightly,the rest of the stata thickness keep stability.Through the system of lithological division,this paper elaborates on the features of the main rock types,distribution and forming conditions;At the same time,studied the sedimentary microfacies,established the descriptive picture of single well sedimentary facies,the picture of sedimentary facies contrast section,and the drawing of sedimentary facies distribution model,it is concluded that the upper Yingshan formation of eastern lungu was bioherm beef beach facies and beach interact sea facies of the regional open platform facies.The period of Yijianfang formation ordovician,the sea was regionally shallow,and appeared the point reef deposits between shallow deposits,which belong to open platform facies.The Tumuxiuke formation is sinking platform-slope facies,their sediments appeared when the open platform of north tarim Ordovician overall balance sank in the wave base plane,formation thickness is almost equivalent.The Lianglitage fomationis for the platform edge facies,nodular limestone is mainly for the deep water deposits of Marginal depressions.When water becomes shallow,it appeared relatively pure platform margin reef sediments.Through reservoir petrology characteristics,reservoir property and reservoir space types,we know that the pore development of the ordovician carbonate rock matrix is poorer,the main reservoir space for all kinds of karst cave reservoir,structural fracture and microfracture system.And the strong karstification in the same direction as layer and cataclasis create by tectonic stress are the control factors of Ordovician carbonate karst reservoir development.On this basis,we have already researched the distribution regularity of lateral reservoir,reservoir classification and evaluation,comprehensively evaluated an predicted the regional distribution of favorable reservoir facies belt.As the theoretical and the geological basis is provided for the next step in the oil and gas exploration in the area.