Paper submitted to SEG FWI Beyond Structure Interpretation Workshop, by Khaled Abdelaziz, Hao Xing, Zhuoquan Yuan, Faqi Liu, Carsten Udengaard, Richard Haung, Aurora R. Castelan and Mohamed Hegazy (TGS)
Summary
Full Waveform Inversion (FWI) has revolutionized model building but remains limited by dependence on accurate starting models, low-frequency availability, and complete illumination. When observed and modeled data are misaligned by more than half a wavelength, conventional FWI easily becomes trapped in local minima due to cycle skipping. This study demonstrates that Elastic Dynamic Matching FWI (E-DMFWI), applied to a full azimuth, ultra-long-offset of ~60 km (~30 km minimum maximum offset) OBN survey using the Gemini extended frequency source, can help overcome such limitations. Through a controlled test in which a salt wing was intentionally removed from the initial model, E-DMFWI successfully rebuilt the missing structure and achieved convergence toward the same velocity and elastic fields as the production model. This result confirms the method’s robustness against significant initial-model errors and underscores the synergy between broad-band acquisition design and cycle-skipping-resistant inversion.