Petrel 3D Grid Depth Conversion

Using a standard layer cake approach for domain conversion, Petrel gives you the freedom to select velocity variations for each model layer, while maintaining a time/depth consistency between all faults and horizons.

Benefits

• Provides both standard layer cake approach with interval velocities and use of average velocities down to each horizon
• Handles depth conversion of normal and reverse faulting with the same ease
• The 3D grid depth conversion process maintains and honors the relationship between the faults and horizons, ensuring a consistent model both in time and depth.
• Build models in time or depth. Models constructed in time to be easily converted to depth.

The depth conversion process converts the corner-point grid of the model on a node-by-node basis, including all the grid pillars and faults. The process allows you to analyze the uncertainty in the velocities by using different velocity setups. By reversing the process a time grid can be built from a depth model.

Supported velocity methods

• Linear functions V=VO+kZ
• Surfaces
• Constant velocity

Workflow process

A model (Fig. 2) shows an example of a nonstandard sequence of depth conversion. The zone from H3 to H4 is thin, and the velocity information for this zone is unreliable. You can choose to use a safer method by using a velocity function from H2 to H4 instead; the depth conversion skips horizon H3.