The prediction of recovery percent of water-free stage and its application in the correction of theoretical water cut

Abstract

ABSTRACT Water-free oil production period is an important stage for oil production, prediction and water cut prediction. Because there are many factors affecting the water-free oil production period and the influencing mechanism is complex, it is very difficult to calculate the water-free oil production period. In this paper, the main influencing factors of water-free oil production period are analyzed by the stream tube approach method. The influence law of four influencing factors on water-free oil production period was analyzed and the quantitative relationship between four influencing factors and water-free oil production period were established. The average water saturation of reservoir and water saturation near producers are different which is important for the calculation of theoretical water cut. The quantitative relationship between average water saturation of reservoir and water saturation near producers is established. On this basis, a new method for calculating theoretical water cut is built and is applied to BZ reservoir. The result shows the theoretical water cut calculated by this method is consistent with field data.