Research On Flow Field Adaptability And Development Effect Evaluation Of Extra-high Water Cut Reservoirs

At present,most of the water flooding oilfields in my country have entered the extra-high water cut stage.After a long period of intensive injection and intensive production,the reservoir heterogeneity is more serious,the contradiction between layers is intensified,and the displacement difference is increased.Therefore,it is necessary to develop extra-high water cut.In the future,the evaluation and characterization research will provide guidance for further improving the development effect of the reservoir and enhancing the oil recovery factor.This paper firstly conducts a macro-evaluation of the development effect of water flooding;The flow rate and oil saturation are selected as the flow field evaluation parameters,and a flow field adaptability evaluation model consisting of relative adaptation coefficient,flow saturation difference,absolute adaptation coefficient and equilibrium coefficient is established,which can intuitively characterize the adaptation degree of the region,intuitively judge the flow rate,find the development area of ineffective water circulation and identify the formation of ineffective water circulation channels;The influence of dynamic and static factors on the adaptability index of the flow field is analyzed;The macroscopic evaluation of water flooding development effect was carried out,and 8 evaluation indicators for the development of complex fault blocks during the extra-high water cut period were screened.Namely,the degree of water flooding reserve control,the degree of production of water flooding reserves,the water flooding index,the pressure maintenance level,the water cut rise rate,total decline rate,oil recovery rate of remaining recoverable reserves,relative adaptation coefficient,referring to oil and gas industry standards and oilfield on-site statistical data,determine the evaluation standard in the period of extra-high water cut,and use the fuzzy comprehensive evaluation method for comprehensive evaluation;The flow field adaptability evaluation and macroscopic comprehensive evaluation of the two fault-block reservoirs are carried out,and it is found that in the late high water cut stage and the extra-high water cut stage,the macroscopic evaluation results,water cut and the overall relative adaptability of the reservoir are basically consistent,the daily oil production and the equilibrium coefficient have always maintained a good correlation,and the relative adaptability and flow saturation are classified to adjust the flow field of the reservoir.The adjustment results verify the feasibility and practicality of the flow field adaptability evaluation model.