Velocity model
Velocity model - contains depth / interval velocity models used for time-depth conversion.
Right mouse button on the icon allows to:
- Add velocity model
- Import velocity model
- Clear
- Add folder
Right mouse button on a velocity model additionally allows to:
- Set default
- Calibrate...
- Extract checkshot...
- Rename
- Remove
- Export to Seg-Y file
Import velocity model imports a velocity model from a SEG-Y file.
Extracting a checkshot
In the Data Manager, right-click a velocity model and choose Extract checkshot.... The Extract checkshot from velocity model dialog shows the selected model in a read-only Velocity model field. It samples the model along the selected well trajectories and stores a checkshot containing true vertical depth and one-way travel time under each well.
On a fresh launch, Checkshot name starts with the model name and can be edited. Choose one Well, or enable Batch calculation and select All wells or a project well filter, folder or section. The same checkshot name is used for every selected well.
Set Step [m] (or Step [ft] in a field project) to control the depth sampling interval; its initial value follows the model's depth sampling. The Top depth [m] and Bottom depth [m] labels likewise use the project's depth unit. Top depth starts at zero. Leave bottom depth at Auto to stop at the shallower of the well bottom and model coverage, or enter an earlier depth. The read-only Units group shows depth, time and velocity units.
Click Run to create the checkshots now, or Save to workflow to store these settings without running. A saved task restores its model, name, sampling, depth interval and well scope when reopened; use Save to update that task. When the workflow runs, a batch task resolves its saved well scope again and replaces same-name checkshots without prompting. See Workflows.
If the selected model is not stored as a depth velocity gather, the dialog explains why extraction is unavailable and disables Run and Save to workflow. An interactive run asks before replacing an existing checkshot with the same name. Wells without a trajectory, available model velocity or a usable depth interval are skipped; a step too coarse for the interval also skips that well. The result message lists each skipped well and its reason.
See Also