Potential Enhanced Geothermal Systems in Western Poland—Petrothermal and Geochemical Issues

This study evaluates the potential of enhanced geothermal systems (EGSs) in Poland, focusing on formations composed by igneous rocks, such as crystalline rocks of the Karkonosze pluton and volcanic rocks of the Gorzów Block. A total of 57 rock samples, including granites and rhyolites from these formations, were analyzed for their thermal and geochemical properties to assess their suitability for EGS development. The results highlight the importance of thermal parameters, such as conductivity and diffusivity, in optimizing geothermal exploitation. The measurements reveal that Karkonosze granite exhibits high thermal diffusivity and conductivity, making it a prime candidate for heat extraction. Although the Gorzów Block rhyolites show slightly lower values, their high initial temperatures still promise long-term geothermal viability. Geochemical modelling indicates that mineral precipitation that causes permeability damage is unlikely in these reservoirs. Instead, minor increases in porosity due to mineral dissolution can reduce hydraulic resistance, potentially affecting the performance of the system.