Thermal-Energy Potential of the Liptov Depression

Abstract

The Liptovska kotlina basin represents an intramontaneous depression in the core mountain belt of the Western Carpathians. Results from four geothermal boreholes 1,987 - 2,500 m deep were used for evaluation of geological structure, geothermic and pressure conditions, hydraulic parameters of aquifers, spatial distribution and chemical composition of geothermal waters and their thermal-energy potential.
Geothermal water aquifers in Liptov basin are represented by Triassic dolomites and limestones with the fissure-karst permeability, which were documented by geothermal boreholes at depths of 1,255 - 1,625 m. Their thickness varies between 300 - 1,000 m. Productive length varied from 65 up to 535 m during performed pumping tests. The average value of the intrinsic transmissivity coefficient Tp ranges in the interval 2.41*10-12 - 1.05*10-10 m3, the permeability coefficient kp in the interval 3.82*10-14 - 9.05*10-13 m2.
The geothermal field activity varies considerably, geothermal gradient ranges from 18 to 32 ?C/km and the heat flow density from 44 to 77 mW/m2. At the depth of 500 - 5,000 m there occur waters at 20 - 150 ?C. The chemical composition of these waters is mainly of the Ca-Mg-HCO3-SO4 and Ca-Mg-HCO3 types respectively, with mineralization of 0.4 - 5.1 g/l. Thermal-energy potential of the Liptovska kotlina basin was estimated by distributed parameter model at 34.589 MWt.