The impact of diagenesis on rock properties in geothermal carbonate reservoirs

The present work demonstrates the necessity of detailed studies to reveal the processes that affected carbonates and their rock properties for geothermal exploration between their deposition and the present day. This information can be used to improve predictions of rock properties at reservoir depth. It also highlights that a significant challenge remains to be overcome before the Palaeozoic rock formations in the subsurface of NRW can be successfully exploited through operational geothermal plants. Rock properties of potential geothermal carbonate reservoirs may change even locally due to the diverse tectono-diagenetic history of Western Germany since the Variscan Orogeny. This level of regional/local factors should not be underestimated. The porosity/permeability in carbonate reservoirs can be enhanced by fracturing and dissolution/karstification processes. To gain insights into these processes, petrographic, palaeothermometric, and radiometric data needs to be complemented by laboratory petrophysical measurements to achieve a more comprehensive understanding of the reservoir properties of Phanerozoic carbonates.