On the robustness of sparsity-promoting regularized wavefield inversion with phase retrieval against sparse long-offset acquisitions

摘要: Ultra-long offset OBN acquisitions are suitable for deep offshore subsalt imaging by full-waveform inversion. However, these sparse long-offset acquisitions increase the risk of cycle skipping and can downsample the FWI kernel below the Nyquist rate leading to wraparound artefacts. The first issue has been recently mitigated with the wavefield reconstruction inversion (WRI) method, where a relaxation of the wave equation generated by a feed-back term to the data allows the simulated dataassimilated wavefields to match the data from the first iteration. Then, the subsurface parameters are updated using the data-assimilated wavefields as passive quantities by minimization of the waveequation errors. The second issue related to aliasing generated by sparse acquisition can be partly addressed by sparsity-promoting regularization. We show in this study that the resilience of the WRI to nonlinearity and sampling …