Reservoir Heterogeneity Research Of The Upper Guantao Formation In 7^th Block West Of Gudong Oilfield

The fluvial reservoir of the Upper Guantao Formation in 7th block west of GuDong oilfield has high porosity,high permeability and strong heterogeneity characteristics.Since 1960 s oilfield has experienced a long period of development so far,the water ratio is very high but the recovery is still relatively low,the reservoir heterogeneity is becoming more and more serious.In order to improve the oilfield development effects and the oil recoveries,this paper carries out the research area of reservoir heterogeneity.In this paper,on the basis of predecessors’ research,with combination of core,logging and seismic data in the study area,the analysis of various test data and production data,reservoir physical property study,the logging interpretation model of physical parameters in the study area is established.There are three types of interlayers in 7th block west: muddy interlayers,petrophysical interlayers and calcareous interlayers.The types and distribution characteristics of the interlayers in the study area is established,at the same time,the interlayers’ genesis and property identification standard have been confirmed.The physical property upper limit of interlayers is determined: porosity is 33% and permeability is 500 mD.Heterogeneity of the reservoir has been studied,including the middle of layer heterogeneity,the inside of layer heterogeneity,the reservoir surface heterogeneity and the micro heterogeneity,and form a set of quantitative characterization of reservoir heterogeneity research methods.Finally,I can draw a conclusion that the heterogeneity of the 5th sands group in Guantao Formation is higher than the 6th sands group,and analyze the relationships between the reservoir heterogeneity and the remaining oil’s distribution.