Layer-Stripping Full Waveform Inversion with Damped Seismic Reflection Data

Full waveform inversion (FWI) directly minimizes errors between synthetic and observed data. For the surface acquisition geometry, reflections generated from deep reflectors are sensitive to overburden structure, so it is reasonable to update the macro velocity model in a top-to-bottom manner. For models dominated by horizontally layered structures, combination of offset/time weighting and constant update depth control (CUDC) is sufficient for layer-stripping FWI. CUDC requires ray tracing to determine reflection traveltimes at a constant depth. As model complexity increases, the multi-path effects will have to be considered. We developed a new layer-stripping FWI method utilizing damped seismic reflection data, which does not need CUDC and ray tracing. Numerical examples show that effective update depth (EUD) can be controlled by damping constants even in complex regions and the inversion result is more accurate than conventional methods.