oa High-Frequency Elastic FWI with Automated Decision Making – Improving Imaging in High-Contrast Geological Environments

Full-waveform inversion (FWI) has for more than a decade been an integral part of earth model building workflows, providing high-resolution updates of subsurface properties. In recent years, the value of pushing FWI to high frequencies has been proven to resolve small-scale heterogeneity and provide improved images, either through migration or directly from the FWI-derived velocity model. At the same time, objective functions have developed to provide increasingly robust updates in the most complex environments, with the latest techniques ensuring consistent high-quality results by automating parameter selection. Most recently, the introduction of efficient elastic wavefield propagation for p-wave FWI velocity updates has been shown to provide a step-change in model quality in the most complex high-contrast environments, especially around salt bodies, where elastic effects are known to be significant.

In this case study we demonstrate the application of automated high-frequency elastic FWI for improved imaging of sub-chalk oil and gas reservoirs in the Norwegian North Sea.