Ricerc@Sapienza

Seismic images are the most powerful and used tool in understanding the geological structures in the subsurface. Much of this methodology and expertise has been developed for siliciclastic environments, while for carbonates still a lot remains to be cleared. This is particularly true for faulted carbonates realms where seismic attributes variations are very difficult to be interpreted. The aim of this project is thus to identify and delineate the seismic signature of carbonate-bearing faults. To this aim we will INTEGRATE detailed laboratory-scale rock physics measurements on carbonate fault rocks and larger scale geophysical and borehole measurements to be used as input for the construction of a data-based seismic forward model of carbonate-bearing faults. We will sample fault rocks from three key locations where important regional carbonate faults crop out juxtaposing different carbonate host rocks (from very low to very high porosity and from pure to marly carbonates). Samples will be collected at increasing distance respect to the principal slip surfaces in order to investigate different developed fault rocks. After a preliminary characterization of pristine carbonate rocks, tests on fault rock samples will be run with the experimental deformation apparatus (BRAVA2) to perform laboratory measurements of Vp, Vs and to fully characterize the slip behavior (seismic-velocity weakening or aseismic-velocity strengthening) of these rocks. Derived elastic moduli will be used as input parameters for the seismic forward model that will be built by using Matlab. The obtained seismic images of the different faults, merged with the frictional properties derived from experiments will permit to identify a potentially seismogenic fault with a huge potential for both seismological and reservoir studies.