Author(s)

Shuping Chen¹, Zongpeng Chen²

¹State Key Laboratory of Petroleum Resource and Prospecting, China University of Petroleum, Beijing, China.
²Jackson School of Geosciences, University of Texas at Austin, Austin, USA.

The reactivation of pre-existing faults is a common phenomenon in a basin. This paper discusses the relationship between the pre-existing faults and the newly formed Coulomb shear fractures regarding pore fluid pressures. Based on the Coulomb fracture criterion and Byerlee frictional sliding criterion, an equation relating pore pressure coefficient (λ_e), minimum dip angle (α_e) of the reactive pre-existing fault and the intersection point depth (z) between the pre-existing fault and a newly formed Coulomb shear fault in an extensional basin, is established in this paper. This equation enhanced the understanding on the reactivation of pre-existing faults and can be used to calculate paleo-pore fluid pressures. The bigger the pore fluid pressure in a pre-existing fault is, the less the minimum dip angle for a reactive pre-existing fault will be. The minimum dip angle is less in shallow area than that in deep area. This will be of significance in petroleum exploration and development.

Coulomb Criterion, Frictional Sliding Criterion, Pre-Existing Fault, Pore Fluid Pressure, Reactivation

Chen, S. and Chen, Z. (2018) On the Reactivation of the Pre-Existing Normal Fault. World Journal of Mechanics, 8, 210-217. doi: 10.4236/wjm.2018.85016.