Depth Imaging

Seismic depth imaging is a geophysical technique used to create a detailed representation of subsurface geological structures in their true spatial location (depth). Unlike seismic time imaging, which maps features based on the travel time of seismic waves, depth imaging converts travel times into accurate depth measurements using velocity models. With this method, horizons are more likely to be positioned correctly, rather than be distorted (too deep or too shallow) by the presence of a shallower feature with distinctly faster/slower velocity.

Depth migrating seismic data with a reliable velocity model is great for accurately positioning subsurface features, enabling better decision-making for energy projects. In oil and gas exploration, precise imaging of sub-salt structures is crucial to identifying viable reservoirs and minimizing drilling risks in complex geological environments. For offshore wind development, accurate depth migration helps map shallow gas pockets and very soft sediments that can impact foundation stability and increase installation costs.

Velocity Model Building (VMB) is performed using either high resolution gridded tomography (HRTomo) or full waveform inversion (FWI), which utilises the complete seismic wavefield, or a combination of both. Anisotropy can be incorporated with or without the availability of wells. Lateral and vertical variations in Q can also be derived and incorporated into the final migration.

Our processing software package, DUG Insight, is also a renowned interpretation toolbox, that allows the geologist and geophysicist to collaborate inside the same project to assess the accuracy of each velocity model update. ​

The seismic data and velocity model can be migrated using conventional or Least-Squares (LS) versions of Kirchhoff PreSDM or Reverse Time Migration (RTM) algorithms. All with extensive options to account for anisotropy and Q (Earth’s attenuation).

Contact one of our geophysicists below for advice on your depth imaging projects.

Related services: FWI, Pre-processing;