Characteristics Of Low Permeability Layers Of Dolomite Reservoir And Geological Modeling Of Block YM32,Tarim Basin

The existence of low permeability layers in reservoir can separate oil reservoir into several unconnected flow units,which can affect the movement of fluid.In the late stage of oil and gas field development especially,the distribution characteristics of low permeability layers determine the distribution of residual oil.Currently low permeable formation research mainly focus on clastic rock reservoir,however the dolomite reservoir in Block YM32 of Tarim basin has entered the late stage of development with a high water content of 88%.According to the underground identification and field profile research,a large number of low permeable layers have been found in the research area through the eombination of dynamic and static data.So combined with the regional geological survey of the study area,through the thin section and analysis of laboratory data,the distribution of high-quality reservoirs and low permeability layers were forecasted in this thesis,providing the basis for the later development of oil and gas field based on the characteristics of reservoir and low permeability layers,3D geological modeling.The study shows that the reservoir lithology of the Block YM32 is mainly fine crystal and medium crystal dolomite,with a small amount of micritic crystal,powder crystal and coarse crystal dolomites.The reservoir space is dominated by pore-type,cavern-type and small pore and cavern-type.There are six low permeability layers in the study area,which develop steadily and are mainly controlled by the facies and sequences.The horizontal distribution range of low permeable layers is predicted by using thin layers reflection coefficient inversion and field outcrop section model.According to the data of core,logging,seismic and other data,a 3D geological model is established by using Petrel 2014 software based on the idea of "sequences control rock facies and rock facies control reservoir",and the distribution characteristics of low permeability layers are predicted.The detailed geological model can help improve the accuracy of reservoir numerical simulation,reveal the chaiaeteristics of oil and water controlled by low permeability layers,predict the distribution characteristics of remaining oil,and provide important basis for the rolling development of oil reservoir.