Permeability Heterogeneity in Fault Damage Zones and Its Relationship to Deformation Band Connectivity

We calculated the width of a connected deformation band volume, or ‘effective damage zone’ using proportion of connecting nodes in the damage networks, and calculating the distance from the fault at which the network is not connected. The geometry of deformation bands in the damage zone (parallel strike to the fault) results in directional differences in fluid flow reduction through the networks. Fault normal flow would be reduced significantly more than fault parallel flow through connected deformation band networks, only if the deformation bands were connected. An increase in the proportion of deformation bands to matrix, moving towards the fault, along with increases in connectivity would result in very low fault normal permeability within the effective damage zone.