Summary
The Woodford Shale is one of the more important resource plays developed during the last decade. Unlike the more widely studied Barnett Shale, open fractures not only exist but can significantly enhance production (Portas, 2010). Using coherence and most-negative principal curvature, Gupta (2012) in the Anadarko Basin and Guo et al. (2010) in the Arkoma Basin were able to map a network of lineaments that correlate to subtle faults seen on the vertical seismic data. In both cases, these "faults" also give rise to anomalously low acoustic impedance. Such a correlation can be explained by two hypotheses: one that explains the low impedance anomalies as an artifact of seismic imaging, the other that explains the anomalies as fractures and faults that propagate into the Woodford Shale from the underlying Hunton Limestone. In this paper we use 2D pre-stack finite difference modeling of faults and fractures followed by pre-stack depth migration and inversion to evaluate these two possibilities which supports the hypothesis that the low impedance anomalies are correlated to fractures and karsting in the underlying Hunton Limestone.
