FAULT ZONE PROPERTIES IN THE ROMAN VALLEY QUARRY RESERVOIR ANALOGUE: INSIGHT FOR WELL LOGS, CORE AND FIELD DATA

Carbonate rocks represent important natural reservoirs of geofluids (e.g. mineral and hydrothermal waters, geothermic fluids, oil and gas) in which containment and migration are strongly influenced by the “fracturing” state of the rocky masses. According to several field-based research papers, fault zones exert a first order control on fluid flow and accumulation in the subsurface. In order to implement this information into predictive modeling tools, helpful to optimize the exploitation of oil reservoirs, it should be useful to integrate field-based data together with wells-based data (generally consisting of core and well logs analyses), usually employed by oil company workers for the formation evaluation. The present work aims at filling this cognitive gap by integrating field, core and well log data collected on a fault zone cropping out in a reservoir-analogue, located in the Roman Valley Quarry (Majella Mountain, Italy). The characterization of cores and geophysical data (from well logs) aims to: (i) perform a detailed structural analysis from well cores and optical scanner images data; (ii) calculate both matrix and fracture porosities of the collected cores; (iii) find the relationships among the measured porosities values and the geophysical logs; (iv) develop a method to discriminate, from well log data, the matrix porosity from fracture porosity. The comparison of well log, core and outcrop data of a fault zone crosscutting an analogue carbonate reservoir allow us to correlate the fracture characteristics with the geophysical properties. We also define some issues, and propose practical solutions, to compute the petrophysical parameters characterizing both matrix and fracture net pore volume in a carbonate rock.