Pulse diffraction by a curved half plane
Diffraction of a pulsed point source near a hard half-plane cylindrically curved near its edge is analyzed by the geometrical theory of diffraction. Source and receiver are both on the convex side of the curved surface. The solution includes first and second order edge diffracted fields: those of the edge and creeping wave and those of the discontinuity in curvature at the junction between the cylindrical segment and the plane surface. The latter are particularly strong near the reflection boundary, as shown in numerical results for zero offset between a source receiver pair. Creeping waves are calculated across their transition boundary using Fock functions and into the shadow region where they are strong enough to be observed experimentally.
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The use of diffraction imaging to complement the seismic reflection method is rapidly gaining momentum in the oil and gas industry. As the industry moves toward exploiting smaller and more complex conventional reservoirs and extensive new unconventional resource plays, the application of the seismic diffraction method to image sub-wavelength features such as small-scale faults, fractures and stratigraphic pinchouts is expected to increase dramatically over the next few years. “Seismic Diffraction” covers seismic diffraction theory, modeling, observation, and imaging. Papers and discussion include an overview of seismic diffractions, including classic papers which introduced the potential of diffraction phenomena in seismic processing; papers on the forward modeling of seismic diffractions, with an emphasis on the theoretical principles; papers which describe techniques for diffraction mathematical modeling as well as laboratory experiments for the physical modeling of diffractions; key papers dealing with the observation of seismic diffractions, in near-surface-, reservoir-, as well as crustal studies; and key papers on diffraction imaging.