| Title | Investigation for Geothermal Energy Utilisation in the Town Kosice, Slovak Republic |
|---|---|
| Authors | Andrea Vranovska, Vladimir Benovsky, Vladimir Drozd, Otto Halas and Oldrich Vana |
| Year | 2000 |
| Conference | World Geothermal Congress |
| Keywords | low enthalpy, geothermics, chemistry, water technologic properties, dolomitic reservoir, Kosice basin |
| Abstract | At present the project of geothermal energy utilisation is planned to be set in eastern Slovakia ñ Kosice basin. The total heat output is planned to be 100 - 110 MWt, using 8 production and 8 reinjection wells. Within the first phase of work 3 geothermal wells - vertical GTD-1 and directional GTD-2,3 - were drilled in Durkov geothermal structure (Fig. 1) during 1998 ñ 1999, which proved predictions about the existence of geothermal reservoir. The main inflows of geothermal water come from the upper part of Mesozoic dolomites in the depth 2 100 - 2 500 m TVD, the smaller inflow zones were observed in the lower parts up to the well bottoms in 3 200 m. The transmissivity of the dolomites range from 6,3.10-3 ñ 8,2.10-5 m2/s, degassing point, mainly CO2, is in depth 750 ñ 1195 m. The temperature of geothermal water on the wellheads range in 123 ñ 129?C, dynamic wellheads pressure range in 0,9 ñ 2,2 MPa and free flow flowrate 56 ñ 65 kg/s. Chemical character of water is remarkable natrium chloride type with TDS 29-32 g/l. Origin of the geothermal water according to the chemical and isotopic analyses is supposed to be fresh water salted by trapped sea water in Neogene sediments and consequently penetrated to the lower parts in Mesozoic dolomites. Model calcium-carbonate equilibrium calculations as well as measurements in situ suggest scaling and corrosion properties of the water. The results of wells significantly exceeded expected parameters that seemed to be promising for the realisation of the geothermal energy utilisation project in near future. The feasibility study of the whole project was elaborated. The payback time was calculated for 5 years. |