GNGTS 2018 - 37° Convegno Nazionale

GNGTS 2018 S essione 3.1 595 rocks is a consequence of both conduction and convection phenomena. Moreover, the largest differences in geothermal gradient and heat flux characterizing succession S 1 and S 2 do occur in correspondence with the major structural highs, like that associated to the Ferrara Thrust. For example, this phenomenon is observed at the boreholes of Casaglia (with a gradient difference of 90-100 mW/m 2 ), Ferrara-1 (30-40 mW/m 2 ) and Vignola-1 (50-60 mW/m 2 ). In the latter, the calculated values could be likely attributed to the upwelling of fluids across fracture systems extending to shallow depths as it could be observed in Fig. 3. On the other hand, small variations of the gradient in other boreholes suggest that the heat flux occurs prevailingly or exclusively by means of conductive phenomena. In conclusion, the integrated analysis of deep seismic reflection profiles (Fig. 3) and the estimate of the thermophysical parameters, down to a depth of ca . 3 km, allowed to infer both the horizontal and vertical temperature distributions, which are clearly strongly affected by the geological, hydrogeological and tectonic evolution characterizing the region. Accordingly, the most promising areas in terms of potential geothermal reservoirs and their exploitations have been recognized in a sector of the eastern Po Plain. References Bigi G., Cosentino D., Parotto M., Sartori R. and Scandone P.; 1990: Structural Model of Italy: Geodynamic project, C.N.R.. Firenze, S.EL.CA. , scale 1:500.000, 6 sheets. Horner D.R.; 1951: Pressure build-up in wells. Proceedings of the Third World Petroleum Congress, 2, 924–931. Mistroni L.; 2016: Interpretazione di un profilo sismico attraverso l’arco di Ferrara centrale. Tesi di laurea, Università degli Studi di Ferrara. Pasquale V., Gola G., Chiozzi P., Verdoya M., 2012: Heat flow in the Western Po Basin and the surrounding orogenic belts. Geophys. J. Int,, 190, 8-22. Pasquale V., Chiozzi P., Verdoya M.; 2013: Evidence for thermal convection in the deep carbonate aquifer of the eastern sector of the Po Plain, Italy. Tectonophys., 594, 1-12. Robertson E.C.; 1988: Thermal properties of rocks. USGS Open-File Report 88-441. Zschocke A.; 2005: Correction of non-equilibrated temperature logs and implications for geothermal investigations. J. Geophys. Engin., 2, 364-371. Viganò A., Della Vedova B., Ranalli G., Martin S., Scafidi D.; 2012: Geothermal and rheological regime in the Po plain sector of Adria (Northern Italy). Ital. J. Geosciences, 131 (2): 228-240.