3D anisotropic full-waveform inversion for complex salt provinces

Seismic imaging and inversion become extremely challenging when dealing with salt structures. Conventional state-of-the-art full-waveform inversion (FWI) fails to recover those features in areas where salt is present. A widely used solution in industry, however, involves substantial human interpretation. In this study, a regularized isotropic full-waveform inversion that penalizes the velocity drops in depth is introduced to recover the top parts of salt bodies. Then, an automatic salt flooding is applied to reconstruct deeper parts of the salt. Finally, in order to improve the accuracy of the inverted model, which is strongly affected by anisotropy, an anisotropic FWI is used to update the velocity model. We tested the approach on both synthetic and field datasets. Our FWI results revealed satisfying salt recovery as well as detailed velocity features in areas close to salt bodies.

Automated summary

Seismic imaging and inversion face challenges when dealing with salt structures. Conventional state-of-the-art full-waveform inversion (FWI) fails to recover salt features. A widely used solution involves human interpretation. This study introduces a regularized isotropic FWI to recover the top parts of salt bodies and an automatic salt flooding to reconstruct deeper parts. An anisotropic FWI is used to update the velocity model and improve the accuracy. The approach showed satisfying results in both synthetic and field datasets.