Seismic fracture detection in the Second White Speckled Shale: Anisotropic perspectives on an isotropic workflow

David Cho, Craig A. Coulombe, Scott McLaren, Kevin Johnson, Gary F. Margrave

Seismic methods for fracture detection typically require an azimuthal analysis of the recorded wavefield. However, conventional data acquisition practices often provide insufficient azimuthal and offset coverage for proper application of azimuthal techniques. Therefore in most cases, alternative methods must be used for fracture detection.

This study investigates the ability of seismically derived isotropic properties in the delineation of fractures within the Second White Speckled Shale. Fracture systems with structural controls were identified through attributes that are sensitive to changes in the structure of the seismic image. In addition, elastic properties were derived from the seismic measurements to investigate the conditions that control fracture formation in a given stress environment. Travel-times through anisotropic models were also analyzed to determine the propagation response in the presence of fractures. The analysis yields a set of attributes that are sensitive to fractures and are used in the reduction of uncertainty for the delineation of the associated fracture systems.