Abstract: This method provides a means of determining the optimal injection and production rates for a given well pattern for use in enhanced recovery projects in petroleum reservoirs. A streamtube model for the pattern for a given injection and production rate is determined. Data from this model are plotted as a function of percentage of streamtubes exhibiting breakthrough to production wells versus time. A series of these graphs is plotted for different injection-production rates, and the model exhibiting the highest percentage of streamtube breakthrough within a reasonable time is selected.