Seismic inversion for engineering applications in unconventional reservoirs

Due to their low permeability, achieving economic production from unconventional reservoirs entails hydraulic fracturing to increase the surface area in contact with the reservoir. Important to the design of efficient hydraulic fractures is an understanding of pore pressure, the orientation and magnitude of principal stresses, the geomechanical properties of the rock, and the density and orientation of any natural fractures. Such understanding can be achieved by building a predictive 3D mechanical earth model, using amplitude variation with angle inversion of properly processed, imaged, and well-calibrated surface-seismic data. This approach requires quantifying the intrinsic anisotropy of shales, azimuthal anisotropy due to the presence of natural fractures and horizontal stress anisotropy, as well as transforming dynamic elastic properties to static elastic and geomechanical properties.