A reservoir model and production capacity estimate for Cambrian geothermal reservoir in Kretinga, Lithuania

Abstract

The Kretinga geothermal field in West Lithuania was treated as a model case for geothermal utilization of wells which will be abandoned after the finish of oil production. The field was chosen due to the geothermal anomaly existing in this area and because of quite favourable reservoir conditions. The Cambrian geothermal reservoir in the Kretinga oil field is briefly described with data from 7 drilled wells. Formation temperatures and initial pressures for each well are estimated and a conceptual reservoir model presented. In this study the production potential of the deep Kretinga geothermal reservoir with reinjection was estimated. The results indicate that reinjection can increase its production by 80% from the 1997 production rates with drawdown limited to 100 m. Thermal breakthrough of the reinjection was investigated. The results show that by locating the reinjection wells at about 800 m from the production wells it will not occur within 30 years. However, those results need to be tested with a tracer test and a design is given for that. Finally a three dimensional numerical model was developed for the Kretinga geothermal reservoir, the first of its kind for a geothermal system in Lithuania.