Evaluation of the Water Flooding Development Potential at High Water Cut Reservoirs with the Multi-Level Fuzzy Synthetic Evaluation Method

Abstract

At present, most of China's onshore oil reservoirs are facing big challenges as they have entered the stage of high water content. For high water cut reservoirs, conventional reservoir engineering methods, such as the production decline curve analysis method, the water drive characteristic curve analysis method, the forecasting model method and so on, are away from the actual situation at some degree in predicting the difference of water flooding development potential. And it is hard to meet the requirements in mid-to-late stage of high water cut reservoir development by accurately judging the development potential. This paper, through reservoir response, optimizes the elected geological and development indexes that can reflect the water flooding development potential combining the grey correlation and Delphi methods. Then the multi-level fuzzy synthetic evaluation method was established by combining the analytic hierarchy process and the fuzzy evaluation process considering the geological and development factors, and was applied to objectively evaluate the water flooding development potential. At last, through case study of the Baikouquan Reservoir in the 21st Wellblock, it has been proved that this method is effective and feasible.