Method to Predict the Reasonable Injection Adjustment at the Later Stage of Waterflooding Oilfield with High Water-cut

At the stage of oilfield with high water-cut, the yield declines year by year. In order to slow down its declining rate, the annual water injection ought to be increased year after year for the water flooding oilfield. Then it is important to determine the reasonable water injection so as to control the rising rate of water-cut and to extend the lifespan of the oilfield. In this paper, the yield declining equation along with the typical water flooding characteristic equation I is used to calculate the range of annual injection adjustments between the two extremes of the maximum decline and no decline at the later stage. The results are meaningful to guide the overall development of the oilfield.