The Geomechanics of Shale Completions and Stimulation

Neal Nagel
Itasca Houston, Inc.

While the geomechanics of hydraulic fracture stimulation in shale gas and shale oil reservoirs can be complicated, there are (at least!) two critical issues to remember. First, hydraulic fracturing – particularly in naturally fractured formations like shale – is a fully coupled, hydrothermo- mechanical process. In essence, this means that we cannot solve for the mechanical effects of opening a mode 1 hydraulic fracture and/or natural fractures and then separately evaluate for flow effects like leakoff without the potential for significant errors. Secondly, and not divorced from the first issue, is that generated microseismicity during hydraulic fracturing is a manifestation of rock failure – itself a coupled hydro-thermo-mechanical process.

During this presentation, the focus will be on a discussion of the critical geomechanics concepts and ‘accepted’ knowledge about hydraulic fracturing in shales as related to natural fracture behavior, stress shadows and the geomechanical effects from multi-stage horizontal well stimulations, stress shadow effects from multi-well completions, and the relationship between geomechanics and microseismicity in shale stimulations.

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