Numerical exploration for medium - low enthalpy fluids in Roman Geothermal Province

Abstract

his work explores the potential of numerical modeling for the study of magmatic heat source of the Roman Geothermal Province (RGP). RGP is one of the largest geothermal areas in Europe, related to the presence of Quaternary volcanic complexes (Giordano et al., 2014). Extensive geological, geochemical and geophysical studies allowed to define the existence of a regional geothermal reservoir made of Meso-Cenozoic carbonatic successions characterized by secondary permeability. The regional reservoir is covered by syn-orogenic and post-orogenic pelitic successions that allow the instauration and persistence up-today of accessible high enthalpy geothermal resources in correspondence of the main Quaternary calderas and of medium to low enthalpy resources away from them, driven by lateral advection of fluids.There are no studies that have attempted to model the first order features of the RPG. The numerical code used in this thesis is the open source HEAT3D (Wohletz, 1999), that models the thermal state within a heterogeneous material with heat sources. We assume the existence of a heat source at depth, transferring the heat to other layers by conduction/convection and evaluate its characteristics.The implemented numerical modeling for the City of Rome area extends from the Monti Sabatini area to the Colli Albani area.Two different configurations are implemented.•The first is purely conductive;•The second is convective-conductive, under the City of Rome.In the conductive numerical model, temperature gradients increases, passing from the initial 20 K/km to 28 k/km -35 K/km in the first 1,000 m depth, relevant for the low enthalpy geothermal energy production.In the conductive -convective simulation, thermal gradient increases expecially till -2,000 m, passing from the initial 20 K/km to 34 K/km -42 K/km. This result pushes towards a more intensive exploration of medium -low enthalpy geothermal energy.