Uncertainty Analysis In Geologic Model Of Tight Sandstone Gas Reservoir

In order to develop oil and gas reserviors economically and effectively,it is necessary to build more credible geological models.Therefore,quantifing and reducing the uncertainties in the process of geological modeling are becoming more and more important in the oil and gas field development reserch system.Sulige tight sandstone gas reservoir has low abundance and high reserves.The contact relation of the sand bodies is not clear in the reservoirs with strong heterogeneity.This paper focuses on a area in Sulige tight sandstone gas reservoir.While investigating,the geological data,well log data and dynamic data of well production have been fully studied,together with the use of the modern sedimentary model,outcrop analysis of the similar areas and dissection of sand bodies in dense well area,finally a geological knowledge data-base about the sand bodies in braided river and meandering stream deposit in the study area is established.Besides the control of hard data,facies-controlled modeling is also used when building the geological models.Interference testing and dynamic analysis are used to evaluate the uncertainty of the model of reservoir.In this paper,a new method about uncertainties quantitative evaluation is raised based on digital outcrops.The result of geological model under restrain of present wells is discussed.Then local uncertainty of the model is discussed through interior connectivity analysis of effective sand bodies.Finally,the optimal models are analysed based on the results of uncertainty analysis.