High-fidelity complete wavefield velocity model building and imaging in shallow water environments – A North Sea case study
Grunde Rønholt, Øystein Korsmo, Samuel Brown, Alejandro Valenciano, Dan Whitmore, Nizar Chemingui, Sverre Brandsberg/Dahl, Volker Dirks and Jan-Erik Lie
Journal name: First Break
Issue: Vol 32, No 6, June 2014 pp. 127 - 131
Info: Article, PDF ( 1019.17Kb )
Price: € 30
Accurate sub-surface image reconstruction from prestack depth migration of surface seismic wavefields requires precise knowledge of the local propagation velocities between the recording location and the image location at depth. Such velocity information has traditionally been derived by tomographically inverting residual moveout information of common image gathers, which have been computed using an initial velocity field. This methodology proves to be challenging in shallow water environments, particularly when strong and rapid velocity variations in the very shallow overburden need to be recovered, while moveout information from reflected arrivals is very sparse or not available.