High-Resolution Fwi Imaging - an Alternative to Conventional Processing

The inclusion of reflections in full waveform inversion (FWI) not only allows for deeper velocity model updates but also provides an opportunity to simultaneously generate an intercept-reflectivity model derived through multi-scattering least-squares imaging. We demonstrate a novel approach to simultaneously invert for velocity and intercept-reflectivity vector at high frequencies directly with FWI. These models can be achieved ahead of the conventional processing and imaging workflow and are fit for quantitative analysis. Given that FWI can use the primaries, multiples and ghosts present in the raw field data, the resulting intercept-reflectivity image is generated from signals which more completely sample the subsurface in comparison to, for example, LS-RTM or Kirchhoff which use only primaries. This yields improved illumination, a reduction in acquisition footprint and an increase in resolution. The derived velocity model is suitable for use in conventional imaging techniques, if desired, and demonstrates an improvement in image gather move-out without the need for further conventional reflection tomography. This approach is demonstrated to high frequency using a dataset from the Australian North-West continental shelf.