Research On Discontinuous Boundary Prediction Technology Of Fluvial Facies Reservoir Based On Mathematical Morphology

In the Mesozoic and Cenozoic Oil and gas basins in China,the proportion of the oil and gas reserves of the fluvial facies reservoirs in the proven reserves is about 46%,which can be called abundant reserves.However,with regard to the existing technical conditions in China,the average recovery rate of oil and gas is only about 30%,which means that about 70%of the oil and gas remained in the underground.And because of the limitation of reservoir heterogeneity,about 35%of the remaining oil and gas become movable remaining oil.In order to improve the oil and gas recovery rate and the remaining oil recovery,how to understand reservoir heterogeneity from seismic exploration has become the key of current research.In the process of oil and gas exploration and development,the partition of the seepage unit inside the reservoir becomes very important because of the influence of the reservoir heterogeneity.For a fluvial facies sandstone,especially inside reserve unit,it is composed of different scale and level of sandstone complexes.The interface between adjacent sandstone complexes has a different degree of restriction on fluid seepage,that is,"seepage barrier".Therefore,the study of reservoir heterogeneity can recognize the distribution of oil,gas and water in the reservoir.And through seismic attribute analysis technology to depict the discontinuous boundaries affecting fluid flow in reservoirs will become an effective technical to improve the oil and gas recovery rate and the remaining oil recovery and injection-production well system optimization.With all kinds of new methods applied to seismic exploration technology,such as mathematical method,signal process technology and computer technology,we can extract more geological information from seismic data.Based on the complex spatial distribution and connectivity of fluvial facies sandstone,this paper summarizes the algorithm of seismic attributes,and further excavates the information of discontinuous boundaries implied in seismic attributes,and propose the method of optimizing seismic attributes and its process by using mathematical morphology.Meanwhile,we designed a generalized morphological edge preserving filtering method and a full range of morphological weighted fusion discontinuity boundary detection method.And through this method,we have fine depicted the boundary of the reservoir and made a reasonable understanding of the heterogeneity of the reservoir.Finally,we applied the method to the oil field work area and achieved good results.