Examples of Seismic Fracture Detection in the Midcontinent of North America
Donald C. Adams, and Mark Meadows
4th Wave Imaging, Aliso Viejo, CA
Integration of fracture information derived from diverse sources including well log, outcrop and seismic reflection data is important for improving petroleum production from fractured reservoirs. Seismic methods provide constraints on the extent and connectivity of fractures which geologic methods alone cannot provide.
In this study we will demonstrate several seismic techniques that are useful for fracture and fault characterization, including seismic continuity, advanced spectral decomposition, curvature analysis and seismic azimuthal p-wave amplitude analysis. Each method is sensitive to different physical characteristics of fractured rock. We will show by example that the application of multiple seismic methods integrated with geology and well information produces an optimum analysis of a fractured reservoir.
Our examples are from the Barnett Shale, Fort Worth Basin, Texas and Teapot Dome in Wyoming. The Barnett Shale is an unconventional tight gas reservoir whose wells must be hydraulically fractured during completion in order to stimulate production. Mapping of fractured areas using curvature analysis and azimuthal amplitude variation aids in avoiding areas of existing fractures and karsting which can interfere with successful well completions. Teapot Dome is a tight oil reservoir with several stacked pays situated on a thrust-related anticline. Fault and fracture areas are mapped using a combination of seismic continuity, advanced spectral decomposition and curvature analysis integrated with geologic information. Results from these two areas will be compared to applications of similar methods to other reservoirs.