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Diffraction Imaging by Prestack Reverse-Time Migration in the Dip-Angle Domain
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, 79th EAGE Conference and Exhibition 2017, Jun 2017, Volume 2017, p.1 - 5
Abstract
Prestack image volumes may be decomposed into specular and non-specular parts by filters defined in the dip-angle domain. For space-shift extended image volumes, the dip-angle is derived by local Radon transform in depth and midpoint coordinates, followed by an averaging over space-shifts. We propose to incorporate space-shift extended reverse-time migration (RTM) and dip-angle decomposition for imaging small-scale structural elements, considered as seismic diffractors. A suitable dip-angle construction of a specularity filter rejects the dominant reflectors and enhances diffractors and other non-specular image content. The filter exploits a clear discrimination in dip between specular reflections and diffractions. We demonstrate the dip-angle filter with 2D synthetic examples, and show its robustness against migration velocity errors. Our method for diffraction imaging delivers space-shift and angle-domain image-gathers, simultaneously, and obviously enrich the processed material on the interpreter’s desk.