CHARACTERIZATION OF GEOTHERMAL RESERVOIRS PARAMETERS IN POLISH PART OF CARPATHIAN FOREDEEP - Carpathian Journal of Earth And Environmental Sciences

Geothermal energy in Poland is accumulated in four geothermal provinces characterized by different geological conditions and varied geothermal water parameters. One of them is Fore-Carpathian geothermal province, which has not been before a subject of comprehensive geothermal research. Characterization of geothermal reservoir parameters as well as estimate of geothermal waters parameters accumulated in these rocks in the Polish part of Carpathian Foredeep were carried out in order to indicate the best locations for different types of geothermal energy utilization. The analyses show that the geothermal potential for recreation and/or balneotherapy is much higher than that related to applications for heating purposes. The best parameters are revealed by waters accumulated in the Devonian and Carboniferous carbonate sequences of the western part, the Middle Jurassic sandstones in the eastern part, the Upper Jurassic carbonate rocks and the Cenomanian sandstones in the central part of Carpathian Foredeep. The problem of geothermal water utilization in research area is related to low discharges of wells. Only the Cenomanian aquifer is characterize by high discharges (up to 200 m³/h) over the whole area of its occurrence. Potential discharge of wells in other reservoirs does not exceed 60 m³/h. Mineralization of groundwaters vary in wide range from 25 to 150 g/dm³. Temperatures in the top of perspective aquifers are mostly below 90°C. Highest temperatures (on the order of 150°C) were observed in the Upper Silesia region (western part of the area). In this region the Carboniferous, locally Devonian deposits seem to be prospective for petrogeothermal energy development