Three-dimensional poroelastic analysis of a pressurized natural fracture

Abstract In this paper, a three-dimensional, fully coupled poroelastic, displacement discontinuity method is developed and used to analyze the temporal variation of slip, and opening of a natural fracture in response to its sudden pressurization. Numerical results show when a fracture is pressurized at a level exceeding the normal in-situ stress, it increasingly opens with time as the rock evolves from an undrained state towards a drained state in accordance with the poroelastic theory. And, the pore pressure loading associated with pressurization of the fracture faces induces a time-dependent fracture closure related to rock dilation. The poroelastic analysis of a critically stressed natural fracture that is pressurized below the level required for jacking shows that the potential for fracture failure and slip decreases with the passage of time in response to the pore pressure-induced increase of the normal stress on the joint.