This study provides critical insights into the geothermal reservoir potential of karstified Devonian carbonates, in both their significant promise and the challenges inherent to their exploitation. Karstification was found to substantially enhance effective porosity and permeability, critical parameters for fluid flow, as demonstrated even at the laboratory scale. The measured laboratory values likely represent conservative estimates, as larger-scale karst features at the field scale are expected to improve reservoir properties further. Additionally, mineralogical analyses revealed that dolomitisation also contributes to increased permeability and enhances the geothermal potential of these rocks. To gain insight into the processes of diagenesis and karstification, laboratory petrophysical measurements are combined with diagenetic processes to achieve a more comprehensive understanding of the reservoir properties of Devonian carbonates. Karstified carbonates exhibit the most favourable properties for geothermal applications. Due to the occurrence of several processes leading to karstification, it is necessary to ascertain whether deep hypogenic karstification in relevant reservoir depth has occurred and whether sufficient fluid flow can be guaranteed. Therefore, further multidisciplinary studies are needed to refine our understanding of these reservoirs and ensure their viability for sustainable energy production.
Heinelt et al. (Wed,) studied this question.