Imaging through near-surface absorption bodies with visco-acoustic least-squares migration: a case study from the Northern Viking Graben

Amplitude attenuation and phase distortion of seismic data are byproducts of the Earth’s anelasticity (Q). These effects are exacerbated under regions of anomalously high absorption, such as shallow gas, causing uneven illumination and migration artifacts. We present a case study from the Norwegian North Sea where we utilize single-iteration, least-squares, visco-acoustic, prestack depth migration to produce a stable Q-compensated image. This used high-resolution, p-wave velocity and attenuation models, derived from visco-acoustic FWI. We show this workflow compensates locally for amplitude loss, eliminates the need for a Q-compensation amplitude gain limit, and enhances illumination, event coherency and AVO attributes, while reducing noise