Modeling Hydraulic Fracture Interactions with Natural Fractures

Ravindra Bhide, Milind Deo, John McLennan, and Trevor R. Stoddard
University of Utah

Natural and hydraulically induced fractures will propagate and/or deflate when subjected to sufficient tensile and shear stresses. They will also mutually interact. Any numerical exercise predicting the effect of these mechanical interactions on an integrated fracture network relies on the fracture growth criterion that is adopted. Presented here are the results of a set of simulations carried out using weakly coupled geomechanical simulations for an evolving hydraulic fracture intersecting a prescribed natural fracture network. The simulations have been carried out using a crack opening displacement incremental propagation criterion to represent evolutionary extension, opening and pressurization of pre-existing fractures discretely incorporated in a rock matrix. This allows a natural fracture network to be entered a priori and a hydraulic fracture system to progressively evolve by interacting with these natural fractures. There is episodic growth rather than instantaneous pressurization of each entire intersected fracture. Beyond the nature of the natural fractures, other parameters considered in these numerical calculations include stress field and injection parameters. Realistic field scenarios are explored.

AAPG Search and Discovery Article #90169©2013 AAPG Rocky Mountain Section 62^nd Annual Meeting, Salt Lake City, Utah, September 22-24, 2013