Calculation OOIP in oil reservoir by pressure matching method using genetic algorithm

This paper describes the optimization pressure matching method with a genetic algorithm for the estimation of original oil in place (OOIP). In this method, the pressure of a reservoir is obtained based on the material balance equation by minimizing the difference between calculated and reservoir pressure in order to optimize reservoir parameters suchas OOIP, aquifer constant and water influx data calculated by the aquifer function.The high non-linearity of the pressure matching method makes deterministic classic optimization methods inefficient and unlikely to be successful. Firstly, the solution is dependent on the initial guesses due to the non-convexities of the system equations, and secondly, the convergence of the solution is not always guaranteed.Therefore, an effective optimization strategy combining a two stage approach, genetic algorithm for the initialization and identification of the search zone followed by a simplex search method used to refine the solution, is proposed.Three examples are provided to illustrate the effectiveness of this work by comparing the results of various methods (graphical methods and volumetric estimation) with the results of the pressure matching method.