Generating T-D Pairs from Velocity Model

This process generates checkshots from a chosen velocity model.

Checkshots are generated spaced at regular MD intervals based on a source of velocity data, starting from a manually entered time-depth pair. Some of these checkshots may be removed if they are not required to achieve a specified level of accuracy in TWT.  

Create/resample time-depth

Create/resample time-depth
  1. Set the time-depth survey as the default time-depth pairs in the well.
  2. From the Tool menu, open the Synthetics view.
  3. Select the Current Well.
  4. Right click on the T/D Pair Track and select Create/Resample Time-Depth Survey.
  1. At Mode, select From Velocities.
    • Initial T-D Pair: An initial time-depth pair.  
    • Interval (MD): Minimum MD interval between consecutive generated checkshots.
    • Accuracy (ms): Pairs that affect time-depth conversion below this amount are excluded.
    • Velocity Volume: Velocity volume to use as the input.
    • Velocity Type: The type of data in the selected velocity volume.
    • Velocity Units: The units of the selected velocity volume.  

From Time-Depth Conversion

From Time-Depth Conversion

Time-Depth checkshots can be generated from the project’s pre-configured time-depth conversion model.

  1. To configure the time-depth model, open the File menu and select Configure Time-Depth Conversion. Select a Velocity volume.
  2. Set the time-depth survey as the default time-depth pairs in the well.
  3. From the Tool menu, open the Synthetics view.
  4. Select the Current Well.
  5. Right click on the T/D Pair Track and select Create/Resample Time-Depth Survey.
  6. At Mode, select From Time-Depth Conversion.
    • Initial T-D Pair: An initial time-depth pair.
    • Interval (MD): Minimum MD interval between consecutive generated checkshots.
    • Accuracy (ms): Pairs that affect time-depth conversion below this amount are excluded.