OBN elastic wave velocity modeling and prestack depth migration

Elastic wave Kirchhoff prestack depth migration is an effective approach for high-resolution imaging of complex submarine structures, with its imaging quality primarily dependent on the accuracy of the velocity model. Currently, multi-wave depth domain velocity modeling mainly relies on tomographic inversion and full waveform inversion. However, conventional tomographic inversion applied to multi-wave seismic data imaging suffers from strong non-uniqueness and slow convergence, while the application of elastic full waveform inversion to real data imaging remains exploratory and faces technical bottlenecks. To address these issues, a multi-wave depth domain velocity modeling and migration imaging method integrating layer-matching velocity modeling technology and residual curvature-based grid tomographic inversion is proposed. Both numerical model test and application to actual multi-component Ocean Bottom Node(OBN) seismic data demonstrate that this method produces highly accurate initial depth domain velocity models and significantly enhances the efficiency of velocity model iteration. Furthermore, the multi-wave common image gathers obtained using this method exhibit effective flattened, and the multi-wave imaging profiles show high depth consistency.