Three-Dimensional Poroelastic Simulation of Hydraulic and Natural Fractures Using the Displacement Discontinuity Method

Abstract

A three-dimensional fully-coupled poroelastic displacement discontinuity method is developed and used to analyze the temporal variation of opening and slip of a natural fracture in a reservoir in response to the sudden application of fluid pressure in the fracture surfaces. Numerical results show that a hydraulic fracture opens in an increasing manner with time as the rock moves towards a drained state under the applied stress. The applied pore pressure induces a time-dependent closure caused by the rock dilation. On the other hand, poroelastic analysis of a natural fracture subjected to shear shows that the fracture slip decreases with the time in response to a pore pressure-induced increase in the normal stresses on the joint.