GNGTS 2022 - Atti del 40° Convegno Nazionale

GNGTS 2022 Sessione 3.1 391 Fig. 3 - overpressured gas accumulations in the vicinity of a geothermal well (adapted from Omodeo Salè et al., 2020). such as thermal conductivities can be derived from temperature measurements by means of inverse geothermal modeling, integrated with geophysical observations with data assimilation techniques, to identify potential geothermal “sweet spots” and deviations from the background model (Fig. 2). Basin modelling techniques can be used to compute pre-drill distributions of pore pressure, temperature, porosity and permeability, thus de-risking the placement of the first well; overpressurized hydrocarbon accumulations such as shallow gas pocket can also be detected, further reducing the risks in the drilling operations (Fig. 3). Finally, natural fractures can be modeled in 3D based on different geological processes (tectonic paleo-stress, association to fault, fault damage zones, thermal cooling, mechanical effects) and from different sources of information, improving the success rates in localizing “sweet spots” for resource targeting. The resulting model can be enriched with offset well data to further characterize the expected heat and fluid flow behavior, as well as the geomechanical stability of the target formations, of the fault network, and of the planned wellbores. Case studies from different areas in Europe will be presented to provide examples of the application of these techniques. References Omodeo Sale, S., Eruteya, O.E., Cassola, T., Baniasad, A. andMoscariello, A; 2020: A basin thermal modelling approach to mitigate geothermal energy exploration risks: The St. Gallen case study (eastern Switzerland). Geothermics, 87, no. 101876, DOI: 10.1016/j.geothermics.2020.101876