An optimization approach to well spacing for gas storage reservoirs

A finite approximation to the conventional diffusivity equation describing compressible fluid flow through porous media has been developed with a view to apply it to the problems of optimum well spacing. An equilateral grid system has been employed to enable uniform well spacing for any number of wells. A numerical model has been developed on an IBM 360 - Model 50 computer, which simulates the pressure and saturation transience in the reservoir due to production impulses. This model has been used to maximize with respect to number of wells, the minimum well bore pressure reached throughout the specified withdrawal schedule. This minimum well bore pressure approaches an asymptotic value as the number of wells increases. Hence, the maximum value of the minimum well bore pressure is considered to correspond to that number of wells beyond which an addition of one more well does not increase the minimum well bore pressure by more than a tolerance. This provides an upper limit for optimum number of wells based on considerations of local economics --Abstract, page ii