section-4d46312
Example 2: Velocity model building using a geologic Model
The Gulf of Mexico subsalt tomographic model is weak but the geological model is relatively strong. The subsalt velocity model is built from the geologic model. Refinements in the geologic model to obtain the best image are performed quickly over a several week period. Image improvements build confidence in the geologic model and lead to additional rewards such as increased prospect size and better information on location.
.
Showline from a subsalt Gulf of Mexico discovery. The three-way structure against salt is well imaged but the final image shows a much better imaged basement structure that is significantly shallower than the original image. The final image makes clear the petroleum system from source to trap including the architecture of the source rock on top of the salt. The slower velocities used in the final image increases the gross rock volume of the trap and risk reserves.
Migrating seismic data uses the velocity model to place the seismic reAectars in the correct location. In this case the velocity model is developed from the basin model which uses sediment type, sedimentation rate and basin architecture to forward model the effective stress in the basin. The rock physics model is used ta construct a velocity volume from the porosity and rock types in the geologic model (Steps 1 C 1 A in the workflow slide in Example 1 ). In practice, this is an iterative approach in which the geologic model is refined to create the best image.
section-0c246cb
Other Services
Unmatched experience across world basins.