Determination of injection-production efficiency using ISODATA fuzzy clustering analysis method

the low efficiency circulation of injected water in formation has seriously effected oil fields efficient development at the late development stage with high water cut. Profile control and water shutoff is an important measure for solving the low efficiency cycle of injected water, and how to select the favorable wells whose injected water cycles inefficiently is the key issue for water shut off and profile control. The present decision-making theory of Profile control and water shutoff disturbed by many artificial factors such as index weight and index boundary in RE decision, so how to judge the wells whose injected water circulation is inefficiently based on the existed preliminary information is the key point. This paper proposes a indicator system for judging low efficient cycle, and then determines whether there is a low efficient cycle and the level of the inefficient according to different dynamic data characteristics using ISODATA cluster analysis method. For the wells that is in invalid cycle be required to take the water profile control and water shutoff decision while the wells in low efficient cycle be suggested a further observation. Thus, this method provides a basis for choosing wells to conduct the profile control and water shutoff technology.