The Constant method builds the simplest possible velocity model: a single interval velocity applied to the full output cube. It is used to produce an initial time-to-depth relationship when no detailed velocity information is available, or as a sanity reference to compare against more elaborate models.

Required inputs

• Datum — the elevation reference for the model. Taken from the project datum; read-only for this method.

Parameters

• Velocity — the constant interval velocity (m/s) applied to every sample of the cube. Default: 2000 m/s.

Workflow

1. Open Setting up the velocity model and select Constant as the creation method.
2. Set the Datum if the default project value needs to be overridden.
3. Enter the constant velocity value.
4. Run the model. The wizard builds interval velocity, average velocity, time, and depth maps filled with the specified value.

Output

A uniform velocity model consisting of interval velocity, average velocity, time and depth map stacks. All layers carry the single velocity value supplied in the wizard.

When to use

• Feasibility studies where only an order-of-magnitude depth conversion is needed.
• A baseline against which more elaborate velocity methods can be compared.
• Synthetic or training projects with no well control.

Avoid this method for production depth conversion — any real depth trend in the section will be flattened.

See Also

• Setting up the velocity model
• Constant layered
• Velocity model QC