A methodol. to optimize CO2 injection into the mature crude oil reservoir, which allows maximum recovery of hydrocarbon resources at the lowest possible cost was proposed. As decision variables, a location of injection wells and a length of the perforations were selected. The concept of optimization of the CO2 injection process was developed by using a genetic algorithm. Three scenarios of the algorithm were used and compared with the results of the process without optimization. Higher crude oil production from the optimized well location than without optimization was obtained.