At DUG, we utilise our proprietary depth imaging toolkit designed and developed by our R&D group. The tools have far-reaching capabilities, having been developed to meet the requirements of the most demanding regions in the world.
Kirchhoff Migration (All true relative amplitude):
- PreSTM or PoSTM - Isotropic or anisotropic (VTI)
- PreSDM or PoSDM - Isotropic or anisotropic (VTI, TTI or tilted orthorhombic)
- BeamM - Isotropic or anisotropic (VTI, TTI, tilted orthorhombic)
- Output sparse or dense angle gathers or SOG gathers
- Isotropic and anisotropic (VTI, TTI)
- Vector offset output (VOO) for high SNR images to aid interpretation
- DUG iRTM for rapid scenario testing
- DUG QRTM to compensate for laterally and vertically varying Q
Reflection and refraction tomography (DUG HRTomo):
- Anisotropic updates
- Horizon-and grid-consistent
- Structure aware regularisation to prevent excessive smoothing across interfaces (including those with dip). Promotes structural continuity in the absence of other information while permitting abrupt changes when required.
- Complete control over which part of the velocity model is updated
- RMO picks are weighted in 3D and have a confidence value
- Reweighting of picks during optimisation in order to minimise the influence of outliers
- Clusterised, allowing an unlimited model size
- Picks can be volume-based, horizon-based, or a combination of both
- Pics can be parabolic or non-parabolic (any shape)
Full stack section before and after DUG MigQ.
Final anisotropic (TTI) RTM section in depth from 2000 to 8500 m. The full stack is overlain with the final interval velocity model. A comprehensive salt model building workflow was an integral part of this 3D project.
Anisotropic (TTI) pre-stack Kirchhoff depth-migrated section from the North Sea (shown in depth from 0 to 6000 m). The final stack and interval velocity model after 5 iterations of anisotropic reflection tomography are shown. [Image is courtesy of Harvest Natural Resources Inc.]
Anisotropic (TTI) pre-stack Kirchhoff depth-migrated section from the North Sea (shown in time from 0 to 6000 ms). The final stack with the final velocity model after 6 iterations of anisotropic reflection tomography are shown. [Image is courtesy of PA Resources]