Geomechanical Interpretation of a ‘Zipper Frac’ in Barnett Shale Wells
As lateral wells’ reaches extend and more wells gets drilled from the same pad, various stimulation patterns and techniques are being tested in search of the optimum approach to hydraulic fracture treatment. ‘Zipper frac’ is a process where two horizontal wells are alternately stimulated with large hydraulic fracture treatments. It is an efficient approach to generating economic production from gas and oil shales such as the Barnett Shale formation in Texas. This approach may provide similar fluid volumes and fracturing energy input to the formation at each individual stage and so provides a very interesting geomechanical situation, where essentially similar perturbations are applied in succession to the Earth. Hydraulic fracture monitoring using microseismic techniques allows at least indirect measurement of these perturbations. Using observations made on recently stimulated laterals, we consider an idealized fracture model, whereby all perforations accept fluid equally and consider the cumulative geomechanical effect of the zipper frac using a finite-element geomechanical simulation of a complete field-case treatment that was performed in the Barnett Shale, Texas. We review the observed microseismic in the light of the simulated geomechanical response and ask whether the simple model can be rejected by the observations.
AAPG Search and Discovery Article #90142 © 2012 AAPG Annual Convention and Exhibition, April 22-25, 2012, Long Beach, California