A new method to predict the water cut increasing rate in water flooding oilfield and its application

The water cut increasing rate is a key parameter for the development effect evaluation and index prediction of water flooding oilfield. Based on A, B, C, D four types of water drive curve, the theory relationship between the water cut increasing rate and the water cut rate is derived. The formula coefficient is determined with relative permeability curves. The results of application in the CB Oilfield shows that for Type A water drive curve, the maximum value of the water cut increasing rate appears at the time when the water cut rate is up to 50%, about which the water cut increasing rate curve is symmetrical. For Type B and C water drive curves, the water cut increasing rate curve declines all the time with the increase of water cut rate. For Type D water drive curve, the water cut increasing rate curve shows the tendency of ascending first and decreasing later, turning at medium and high water cut stage. Through comparing the theory curve with the practical data of CB Oilfield, it can draw a conclusion that Type C water drive curve is more suitable. Thus, it's feasible for us to select the water drive curve according to the law of water cut increasing.