Paper submitted to EAGE Annual 2026
Summary
In recent years, Full Waveform Inversion (FWI) based on elastic wave propagation has gained preference over acoustic implementations for complex imaging projects. When significant mode conversions occur during seismic acquisition (typically associated with strong velocity contrast) an acoustic modeling engine cannot reproduce these observed effects. This limitation often prevents the inversion from converging unless specific data selections, pre-processing steps, or inversion constraints are applied to mitigate the impact of missing physics. A robust modeling engine is essential for successful FWI; however, the choice of objective function, optimization strategy, and parameterization (e.g., Vs, density, impedance, or reflectivity) is equally critical. In this paper, we demonstrate how elastic FWI enables accurate structural imaging at the correct vertical depth and supports geological interpretation, from shallow gas accumulations to lateral velocity variations within fractured basement rocks. The case study is based on an Ocean Bottom Node (OBN) survey from the North Sea. Furthermore, we investigate elastic multi-parameter FWI (eMP-FWI) to derive additional attributes such as density, impedance, reflectivity, and the Vp/Vs ratio.