Applicability of TTI RTM to Structured Land Datasets

Summary Structured land plays demand treatment of topography, anisotropy, and multipathing. Kirchhoff prestack depth migration delivers on the first two of these requirements, but can fail to image adequately at depth because it is unsuitable for multipath imaging. TTI RTM is gaining acceptance in marine applications because of its ability to image complex structures, and here we demonstrate its ability to unlock intractable land structures as well. A complex land dataset with topography has been successfully imaged up to high frequencies required for land processing in this region (90 Hz). Comparison with analogous Kirchhoff results show improvement at depth, and the ability to image structures with greater resolution than in Kirchhoff imaging. The Kirchhoff image is benefitted in the near surface where the ability to carry out post-migration muting is key in removing noise and enhancing structure. Kirchhoff and RTM imaging were also carried out on a dataset formed by regularization and interpolation in the receiver domain. This comparison shows that such data preparation reduces noise and yield clearer images, both shallow and deep. For deep images the RTM image is again superior to Kirchhoff, while the shallow images for this case are of similar quality.