Simulating thepropagationofhydraulicfracturesfromacircular wellboreusingtheDisplacementDiscontinuityMethod

Hydraulic fracturing as applied to well stimulation is analyzed. Propagation of one or more hydraulic fractures from a wellbore that is oriented with either the maximum or intermediate principal in situ stress is studied. A Higher Order Displacement Discontinuity Method (HODDM) with special crack tip elements is used for achieving higher accuracy in simulation of the process. The effect of fluid pressure inside pre-existing fractures is considered. A uniformly distributed internal pressure, which implies injection of a fluid with a very low viscosity is assumed. On the onset of initiation, the crack may reorient itself as it extends from the wellbore, until it becomes aligned with the preferred direction for crack propagation relative to the far-field stresses. Propagation of multiple cracks has been considered to study their interaction. In such cases, some cracks are unable to extend at all, or they arrest after limited propagation, but others can propagate in length relative to earlier developed fractures and even may intersect each other. Also two common perforation phases are studied and best orientations for each one is determined.

Hydraulic fracturing; Well stimulation; Crack propagation; Special crack tip element