Mirror Imaging for Narrow-azimuth, Towed-streamer Data in Shallow-Water Environments

In this paper, Mirror Imaging concepts were successfully implemented on narrow-azimuth, towed-streamer (NAZTS) marine dataset, using preconditioned multiple input data from model-driven shallow-water implementation of 3D SRME, is presented for an offshore Colombian Caribbean case with constant, shallow bathymetry. We have proven that inherent errors in assumptions and approximations underlining NAZTS Mirror Imaging using first-order (receiver-side) water-layer related multiples are negligible in case of a sufficiently smooth and flat seabed morphology. We believe that this implementation of the Mirror Imaging concept on NAZTS marine seismic datasets, predominantly covering the shallow- and flat-bathymetry continental shelf of many passive margins around the world, shall consistently result in improved near-seabed depth images and velocity models, with high potential impact on deeper depth image quality. Applications:

1. Strong integration with shallow-marine surface-wave inversion for near-seabed VS and VP models, and with shallow-marine Early Arrival FWI.
2. Joint Tomography between primary input data with “conventional” tomography and multiple model data and mirror-tomography.
3. Hybrid top-to-bottom velocity building in parallel with the pre-migration processing sequence, from the seabed to basement, thus shortening total turn-around time.
4. Effective planning of high-resolution site surveys in shallow-water environments, through early near-seabed geohazard imaging and interpretation on exploration seismic data.