A New Approach for Determining Optimum Location of Injection Wells Using an Efficient Dynamic Based Method

Well placement optimization is an important step in field development plans. Optimum location of injection wells in a waterflood project ought to be around the drainage boundary of production wells. Therefore, restricting the optimization algorithm domain to the drainage boundary of wells can reduce the number of function evaluations and as a result time needed for the optimization process. Drainage area and drainage boundary can be estimated analytically or by reservoir simulators. However, analytical solutions are based on radius of investigation and are only applicable for simple reservoirs and flows. Also, simulating giant fields requires excessive time. We have developed a computer code based on Fast Marching Method capable of determining drainage area and boundary of production wells with more speed. The main idea is to assign each grid becoming frozen the index of the source point causing frigidity. Each well has been assigned a unique index beforehand. To evaluate the performance of proposed method, drainage boundaries from FMM and streamline simulations were compared. Results showed satisfactory match between the two approaches. Also, FMM-based optimization (search domain restricted to drainage boundary) outperformed simulator-based approach at finding the location of a single injection well in terms of number of function evaluations.