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Comparison of Methods for Rough Sea-Surface Estimation
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, 79th EAGE Conference and Exhibition 2017, Jun 2017, Volume 2017, p.1 - 5
Abstract
Marine seismic data acquired in rough sea conditions present a challenge to successful processing due to the time- and space-dependent perturbations introduced at the source and the relative timing of the ghost at the receivers. It is possible to partially correct for these perturbations via stochastic treatments based on an assumed sea-state, but a more complete deterministic correction requires that we obtain the height profile of wind-driven waves at the surface or some approximation to it. Here we make a comparison of known methods for the estimation of such a profile and discuss some of the practical aspects and limitations in the context of receiver-side de-ghosting. We derive surfaces from a 3D shot record via ghost interference and via low-frequency signal and use these to de-ghost the data. We find generally good correlation between surfaces and in both cases there is uplift in de-ghosting quality when comparing to a flat-sea assumption. The interference method gives greatest improvement at the event from which it is derived but is not suited to generalizing for all times and offsets. The low-frequency method has the advantage in this respect. We propose a hybrid methodology to overcome some of the limitations identified.