Hydraulic fracture reorientation: Does it occur? Does it matter?

Abstract

Hydraulic fracture growth, the dominant method of well stimulation, is controlled by the in-situ reservoir stress state. The in-situ stress state controls hydraulic fracture orientation and, for the most part, the created hydraulic fracture geometry. In-situ stress evolves over the geologic history of a reservoir, leaving footprints of this evolution such as natural fractures and anisotropic permeability. However, on a vastly different time scale of months or even hours, the reservoir stress state can be dramatically altered via fluid production and/or injection. These man-made poroelastic stress perturbations alter the stress magnitude and sometimes even the stress orientation, inducing a change in hydraulic fracture orientation that has been observed on refracture treatments. Fracture reorientation has also been observed on fracture treatments of new infill development wells in mature fields, and is regularly observed on cyclic injection operations in disposal wells.