Normal Fault Damage Zones in Eastern China

We investigate the distribution and thickness of damage-zones for a system of secondary normal faults in the subsurface of the Wangxuzhuang Oilfield, China. Based on seismic variance analysis, we find: (1) Four isolated faults with approximately 2 km length and approximately 200 m damage-zone thickness; (2) The damage-zones of these isolated faults reveal a decaying intensity of deformation from the fault core to the protolith, which fits a power-law form, y = ax−b, similar to that observed in the field; (3) A merged fault with approximately 400 m thickness; (4) A bifurcated fault with approximately 400 m thickness and three linked segments. Damage-zones that consist of several subsidiary faults are thicker than those of isolated faults. The displacement-length analyses of the four isolated faults suggest the constant-length growth of the limestone in this case. We demonstrate the potential to apply seismic variance to systematically characterize damage-zones as potential fluid migration conduits on a basin scale.