A reflection-based efficient wavefield inversion

Full-waveform inversion (FWI) is popularly used to obtain a high-resolution subsurface velocity model. However, it requires either good initial model or low-frequency data mitigate the cycle-skipping issue. Reflection-waveform (RWI) uses migration/demigration process retrieve background that can be as in FWI. The drawback of conventional RWI use least-squares migration, which often computationally expensive, and still prone cycle skipping at far offsets. To improve computational efficiency overcome original RWI, we have incorporated into recently introduced method called efficient wavefield (EWI) by inverting for Born-scattered instead itself. In this case, perturbation-related secondary sources modified source function. Unlike perturbations are calculated naturally part calculation scattered an way. Because reflection-based EWI (REWI) located subsurface, able update along reflection wavepath. inversion, calculate perturbation deconvolution each frequency. After obtaining REWI inverted model, sequential FWI needed We determine validity our approach using synthetic generated from section Sigsbee2A further demonstrate effectiveness approach, test on ocean-bottom cable set North Sea. find methodology leads improved models evidenced flatter angle gathers.