3-D geological-geophysical model and preliminary synthetic seismic reflection modelling along CROP18A line in the Larderello area

Exploration strategies of geothermal reservoirs may significantly benefit from the development of synthetic seismic reflection profiles by confirming the possibility to detect prospective features on acquired seismic reflection data and to calibrate geological-geophysical interpretation and model reconstructions. To be elaborated a synthetic seismic reflection profile requires a conceptual geological model of the subsurface structure and physical properties, which is one of the tasks of the IMAGE FP7 European project (Integrated Methods for Advanced Geothermal Exploration). The Larderello geothermal field is characterized by a shallow and by a deep reservoir. The latter is hosted in the metamorphic basement (Batini et al., 2003; Bertini et al., 1996). In seismic reflection profile, the deepest reservoir is characterized by a strong amplitude reflective signal, the well-known K-horizon, widely observed in several seismic lines (Batini et al., 1978, Accaino et al., 2005) and probably drilled by the San Pompeo 2 well (Gianelli et al., 1997). In this study, geological and geophysical available data have been integrated to develop a new 3D geological-geophysical model of the portion of the Larderello geothermal field drilled by the San Pompeo 2 well. The geological-geophysical 3D modelling was performed using Petrel software. The 3D model has been used to generate a 2-D model for the synthetic seismic modelling of the main seismic units up to the k-horizon along the CROP-18A seismic reflection line acquired within the CROP project. (Scrocca et al., 2013). The exploding reflector approach, developed in Matlab by the CREWES consortium and partly modified by us in this project, has been used to generate the synthetic seismic sections.