Comparison of Thermal Cooldown Estimates in the Russkie Komarovtsy Petrogeothermal Reservoir

Abstract

A comparison of several models to estimate the rate of thermal cooldown in artificial circulation geothermal reservoirs was made for the Russkie Komarovtsy fracture-stimulated reservoir, which will be located near the town of Uzhgorod in the Zakarpate region of the Ukraine SSR. The economic viability of this moderate-temperature resource depends on sustained flow above the minimum abandonment temperature for a period sufficient to recover investment and operating costs. The rate of heat extraction for the required flowrate depends on the fracture distribution in the reservoir. Results of the SGP 1-D Heat Sweep model are compared to approximate analytical and numerical models developed at the Leningrad Mining Institute, based on a common set of initial conditions for the Russkie Komarovtsy - reservoir. The comparison shows that all of the models yielded reasonably similar thermal decline estimates with a satisfactory lifetime of about 25 years to abandonment temperature.