Countermeasure Research On Flow Field Reconstruction In Y Oilfield During High Water Cut Period

After decades of development,most of the old oil fields in China have entered the late stage of high water cut,and the distribution of remaining oil is scattered and difficult to mine.Due to the heterogeneity of the reservoir in the longitudinal direction and in the plane,uneven displacement will occur,which will result in uneven distribution of flow field.As the development progresses,the heterogeneity is more serious,and the difference between the strong water flooding and the weak water flooding increases.Because the injection-production pattern of old oilfields is fixed and the streamline remains unchanged for a long time,a large number of ineffective displacement and water cycle will be formed.Therefore,to further tap the remaining oil and improve the development effect,it is necessary to adopt a series of flow field reconstruction techniques to form a new flow field order,which has great economic significance and broad prospects.In this paper,in view of the development characteristics of the high water cut stage in Y Oilfield,the current distribution of remaining oil and the problems of flow field characterization,it is necessary to study how to carry out flow field reconstruction based on the current flow field distribution.Firstly,by screening a number of indicators,the surface flux is selected as the only index to characterize the flow field,and the surface flux is processed by a reasonable membership function to obtain the flow field strength.Secondly,the classification number and classification limit of flow field level are determined by using the fuzzy C-means clustering method and cluster validity analysis,and a complete flow field evaluation system of water drive reservoir is established to evaluate the flow field of Y Fault Block and provide ideas for flow field reconstruction.In this paper,the current remaining oil distribution law of Y Fault Block is obtained by historical fitting,and a reasonable flow field evaluation system is established to evaluate the flow field of Y Fault Block.Then,the relationship between the flow field grade distribution and the remaining oil distribution is summarized.Finally,a series of flow field reconstruction schemes are formulated to effectively tap the potential remaining oil according to its distribution law.