Discrete Fractures Network (DFN) of the faulted Upper Cretaceous platform carbonates outcropping in the Murge area (Altamura Formation, Murge, Italy)

Discrete Fractures Networks (DFN) of representative volumes corresponding to faulted Upper Cretaceous platform carbonates exposed in Murge were modeled. The obtained DFN models allowed us to compute fracture porosity, and relative permeability distribution of the faulted carbonates, with the aim to decipher the contribution of fault-related deformation on reservoir-scale fluid flow. The study carbonates crop out in Pontrelli quarry at Murge area, Italy, and correspond to an excellent analogue of the hydrocarbon reservoirs currently exploited in southern Italy. The outcrops expose a well-layered limestone affected by both background (diffuse) and fault-related (localized) deformation. Background deformation is made up of two orthogonal sets of joints striking N30 and N120, respectively. The fault-related deformation is represented by two strike-slip fault zones trending N120 (dextral) and N160 (sinistral), which solve an apparent vertical displacements above seismic resolution (about 20m). Minor faults pertaining to the two sets are present within the fault damage zones and surrounding rock volumes. In order to construct the DFN model we elaborated the cumulative frequency distributions and the scaling relationships of spatial and dimensional parameters of both background and fault-related fractures (orientation, length, intensity, and aperture) by mean of scan line and scan area surveys conducted in the field. Finally, the overall permeability tensor of the representative volume was obtained using the software MOVE, which is based on Oda method (1985).