Hydraulic Fracturing Complexity- Interaction between Hydraulic and Natural Fractures

John McLennan
University of Utah

The industry is beginning to use hydraulic fracturing simulations that consider the presence of subsidiary natural fractures or similar discontinuities, and in-situ stresses. The most sophisticated of these models are coupled thermo-hydro-mechanical formulations, where the deformation of natural fractures is contingent on material properties of natural fractures, local pressure and the far-field stresses.

These models provide insight into the complexity of the network of created, reopened and reactivated discontinuities that comprise the productive domain – that is often casually referred to as the stimulated reservoir volume. Progress is being made, industry-wide, in understanding the fracture complexity in different geologic domains – for example, geometric characteristics in a passive margin setting can differ substantially from behavior in a strike slip domain. Examples are provided, suggesting different geologically controlled morphologies resulting from the active interaction between the injected fluids, the pre-existing far-field stresses, and existing discontinuities –faults, fractures and bedding planes – and the consequences for microseismic activity.

AAPG Search and Discovery Article #90178©2013 AAPG Geosciences Technology Workshop, Baltimore, Maryland, July 16-17, 2013