Utilization potentials of the low-enthalpy geothermal aquifer of the Bad Radkersburg – Hodoš pilot area – based on 3D modelling results of the TRANSENERGY project

Abstract

The Bad Radkersburg – Hodoš area is one of the study areas of the project TRANSENERGY (http://transenergy-eu.geologie.ac.at/). The pilot area extends through the NE part of Slovenia, SE part of Austria and continues to the W part of Hungarian state territory. In order to determine the potential effects of different production scenarios on the low-enthalpy geothermal aquifer in the Pre-Neogene basement of the Mura-Zala basin and to provide support for future utilization in this sensitive transboundary area, a numerical model of flow and heat transfer was established. The geothermal model is based on the 3D geological model of the pilot area which is founded on the supraregional geological model of the TRANSENERGY project. The 3D hydraulic and geothermal model was set up with FEFLOW 6.0 modelling software. Delineation of the computational layers is based on geological horizons of the geological model. Due to sparse borehole data only two geological layers were defined, namely Neogene sediments and sedimentary rocks and Pre-Neogene basement. Values of the model parameters were defined in the calibration process. In order to estimate the impacts of the planned utilization in Korovci (SI) on the nearby spa resort in Bad Radkersburg (A) several scenarios were tested. First, 8 production scenarios without reinjection were performed and computed drawdowns were observed. In the next step, 5 scenarios using a geothermal doublet in Korovci were performed and potential cooldown effects of the reinjected water front were determined. The outcome of the modelling as well as the geothermal model itself can be used as a tool for the transboundary management of the thermal aquifer and could support the decision-making process in case of transboundary conflicts.