The Residual Potential of Bottom Water Reservoir Based upon Genetic Algorithm for the Relative Permeability Inversion

Abstract

At present in the offshore oilfield, X oilfield had successfully developed bottom water reservoir with horizontal well. The development mode of single sand body of horizontal well caused water cut rose rapidly and irresistible bottom water coning. The common empirical formula of recoverable reserves obtained through statistical analysis was not applicable to the bottom water reservoir. Under the condition of as high as tens of thousands of time local scour multiple, underground seepage law had been changed. In order to improve the understanding of the remaining potential of bottom water reservoir in the ultra-high water cut stage, this research innovation proposed to carry out the flow tube simulation of the bottom water ridge. In addition, combining with the theoretical research of the quantitative characterization of the water ridge form and the vector permeability, theoretical model was established. At last, the phase permeability curve was calculated from the production data of the ultra-high water cut stage of the bottom water reservoir by combining the genetic algorithm. According to the change of water ridge and oil saturation, the mechanism of end point change of phase permeability curve was expounded, and the effective production radius of water drive oil in bottom water reservoir was put forward, which provided the basis for understanding the potential of oil field and tapping the potential in the future.