Comparison of Seismic Brittleness And Anisotropy to Micro-seismic In the Waltman Shale

A primary control on the effectiveness of induced fracturing in shales is the geomechanical brittleness of the shale in situ. Brittleness can be calculated from wire-line based estimates of Poisson's ratio and Young's modulus (Rickman et al. 2008). Simultaneous pre-stack inversion is used in this study to estimate brittleness in a similar manner by deriving petrophysical properties from conventional 3-D seismic data. Prestack migration within restricted azimuths allows mapping of lineaments not apparent without azimuthal analysis and extends the estimation brittleness to brittleness by azimuth. Micro-seismic data indicate that induced fractures propagate in an azimuth consistent with the seismic analysis, but approximately 30 degrees off of pre-frac predictions based on FMI data. The low size ratio of the induced frac is consistent with the low average brittleness mapped by the inversion.