Optimization of Re-Injection Allocation in Geothermal Fields Using Capacitance-Resistance Models

Abstract

Re-injection of produced geothermal water for pressure support is a common practice in geothermal field management. The re-injection allocation and location selection of the re-injection wells are challenging subjects for geothermal reservoir engineers. The goal of optimization for this type of problem is usually to find one or more combinations of geothermal re-injection well locations and rates that will maximize the production and the pressure support at minimum cost. A simple capacitance-resistance model (CRM) that characterizes the connectivity between re-injection and production wells can determine an injection scheme that maximizes the sustainability of the geothermal reservoir asset. A CRM model is developed for a geothermal reservoir located in West Anatolia, Turkey. It has been demonstrated that this simple dynamic model provides an excellent match to historic data. The developed model is then used together with a nonlinear optimization algorithm to study several hypothetical scenarios.