High resolution diffraction imaging of small scale fractures in shale and carbonate reservoirs

Abstract

Current research in the field of seismic depth imaging has identified a new approach to image with super-resolution fractured zones, fault edges, small scale faults, pinch-outs, reef edges, channel edges, salt flanks, reflector unconformities, injectites, fluid fronts, caves and karst, and in general any small scattering objects, by using Diffraction Imaging as a complement to the structural images produced by reflection imaging. Diffraction Imaging is the imaging of discontinuities in the earth. Diffractions are the seismic response of small elements (or diffractors) in the subsurface of the earth, such as small scale faults, fractures, near surface scattering objects and in general all objects which are small compared to the wavelength of seismic waves. We show results in different areas of the world, in fractured carbonates and unconventional shale reservoirs. Using Diffraction Imaging to identify areas with increased natural fracture density, which correlate with increased production, the reservoir engineers can design an optimal well placement program that targets the sweet spots and minimizes the total number of wells used for a prospective area.