Investigation of the Durkov Geothermal Structure for Utilisation of Geothermal Energy

Abstract

Within investigation of geothermal structure in Durkov three geothermal wells were drilled - GTD-1, GTD-2 and GTD-3 focused on possible geothermal energy utilisation in central heating system in town Kosice. Technical parameters of vertical geothermal well GTD-1 and two directional geothermal wells GTD-2 and GTD-3 prepared them for production and reinjection. Testing of wells proved existence of geothermal reservoir with average free flowrate of wells is 65 Us, wellhead temperature of geothermal water is 125?C and TDS 30 g/1. The source of geothermal water is located in Mesosoic dolomites in depth 2100 - 3200 m. Hydraulic parameters of aquifer and chemical composition of water suggest the prospective geothermal structure which seems to be hydrogeologically and geochemically confined and its utilisation is possible exclusively by reinjection. High TDS (31g/l) and pressure - temperature conditions suggest scaling and corrosion problems during operation. Geothermal heat will be used via heat exchangers in 4 centres and heat will be delivered to central heating system in Kosice. For the realisation of the whole project with heat output 100 MW 8 production and 8 reinjection wells are needed.