Full-wavefield migration in the frequency-wavenumber domain
Shang Huang, Daniel O. Trad
Full wavefield migration (FWM) is an inversion-based migration method that can handle total wavefields, including primary reflections, surface-related multiples and internal multiples. Additional multiple energy can help with improving the subsurface imaging illumination. Previous work focuses on applying full wavefield forward modelling and imaging in the frequency-space domain. In this paper, full wavefield modelling and migration are performed in the frequency-wavenumber (FK) domain, since data in the FK domain is more straightforward to be extrapolated and processed. Phase shift plus interpolation is also combined in the forward modelling to simulate the complex wavefields generated from lateral velocity variations. A deconvolution imaging condition is considered in the imaging procedure to compute more accurate updated model perturbation. The result derived from using full wavefield migration in the frequency-wavenumber domain shows improved reflection response and amplitude spectrum compared with applying primary wavefield migration. This algorithm using multiple reflections provides higher frequency results and better lateral continuity.