Source Deghosting and Demultiple for Calm and Rough Weather Conditions

Source deghosting and demultiple algorithms have been extensively studied but mostly in the case of a flat seasurface. In this work, we consider time-varying sea-surfaces in different types of weather conditions and derive an inversion approach for removal of sea-surface effects. Starting from Rayleighs reciprocity theorem, we model seismic data including time-dependent wavefields scattered at the sea-surface, and highlight the temporal variation of these wavefields through simple synthetic examples, comparing two different weather conditions (calm and rough). We also reveal a limitation of source deghosting in the context of time-dependent wavefields: source deghosting affects the sea-surface multiples and can compromise the success of demultiple processing, which is applied in a later step. Results shows that this limitation is also important under calm weather conditions. To overcome this limitation, we propose simultaneously source deghosting and demultiple, therefore, removing all seasurface effects in one-step. Synthetic data examples are shown using the Sigsbee2B geological model.