Reseacrh On Sedimentary Facies And Resevroir Micro-characteristic Of Upper Guantao Formation In 8^th Block Of Gudong Oilfield

Gudong oilfield is one of very representative oil fields in eastern of China,it put into operation in 1986.The main reservoir in the Upper Guantao Formation of Gudong Oilfield is Ng3-Ng6,namely the object of this paper studied.Meandering river and braided river deposition is the main deposition in Upper Guantao Formation in 8^th block of Gudong Oilfield.Sand body lateral change fast and its heterogeneity is very strong.After more than 30 years of development,the comprehensive water contents up to 95% in Gudong Oilfield.With the deepening of the exploration and development,the sedimentary facies division is not meet the requirements of the current stage any more.Therefore,this thesis choose Upper Guantao Formation in 8^th block of Gudong Oilfieldin as the research object,carry out study of sedimentary facies and reservoir microscopic characteristics,in order to control water content,stable production,enhanced oil recovery.Firstly,under the guidance of the basic principles and methods of reservoir sedimentology,on the basis of logging curve standardization and secondary interpretation,reservoirs of upper Guantao Formation in 8^th block of Gudong Oilfieldin have been divided and correlated mainly by core observation,identification of rock and minerals,and logging curve analysis.Through research,8^th block of Gudong Oilfield in have been divided into 25 small layers,it laid the foundation for study of sedimentary facies and resevroir micro-characteristic.Secondly,utilizing core,logging curve and analysis of test data,sedimentary facies of upper Guantao Formation in 8^th block of Gudong oilfield has been studied,reservoirs in 8^th block of Gudong Oilfieldin have been divided into four sedimentary subfacies?channel subfacies,embankment subfacies,loodplain subfacies and abandoned channel subfacies?and these four sedimentary subfacies have benn further divided into seven types of sedimentary microfacies which includes channel fill,channel bar,channel margin,crevasse-splay,fluviatile flood-lake,river mouth bar,abandoned channel respectively.Finally,on the basis of sedimentary facie study of 8^th block of Gudong Oilfield,strengthen the study of resevroir micro-characteristic,characterize porosity and permeability variation onthe longitudinal and transverse.A conclusion can be draw that reservoir physical property of upper Guantao Formation was controlled by sedimentary microfacies.