Jeremy J. Meyer, Jeremy G. Gallop, Alvin Chen & Scott D. Mildren
Induced seismicity is a threat to the petroleum industries social license to operate. Induced seismicity is the result of shear failure on existing fault and fracture planes induced by fluid injection and a change in pore pressure (Raliegh et. al., 1976). An Alberta operator has experienced casing deformation associated with hydraulic fracture stimulation in the Montneny formation. Multi-finger caliper data indicates that the casing is failing in shear with the general orientation of the failure plane being interpretable from the data. This failure occurs in wells proximal to existing fault and fracture networks, but varies in risk between formations. The mechanism is the same as that result in larger scale induced seismicity. Consequently, understanding the casing failure may provide additional understanding of induced seismicity.
A 3D analytical geomechanical model was constructed to understand the variation in casing deformation between formations. The model indicated that the lower zone which is more susceptible to casing deformation is characterised by higher stress anisotropy and greater shear stress resulting in a greater risk of induced shear failure causing casing deformation.