What are some good ways to create synthetic velocity models?

The following describes the workflow to create a Vo+kz velocity model with varying gradients between horizons for the purpose of time/depth conversion.

Create a simple V0 model

Create a simple V0 model
  1. In the Process tab, click on the Add icon and select New Process.
  2. Create a Volume Maths process and type a Name for the process. Click OK.
  3. In the Details Panel, at Formula, type the formula 1500 to create a velocity model at a constant value of 1500.
  4. Under the Output Extents section, select a 3D survey.
  5. Enter the appropriate Inline and Crossline extents for the model.
  6. Models can be created in TWT or TVDSS, depending on the domain selected in the output extents.
  7. The velocity model will appear in the Volume tab.

Assign a velocity class to the model

Assign a velocity class to the model
  1. In the Control Panel, open the Volume tab.
  2. Double click the velocity volume or right-click and select Configure 'Volume'.
  3. At Class, select Velocity (Interval) from the drop-down list.
  4. Click OK.

Create a simple V0 + k(z) model

Create a simple V0 + k(z) model
  1. In the Process tab, click on the Add icon and select New Process.
  2. Create a Volume Maths process and type a Name for the process. Click OK.
  3. In the Details Panel, at Formula, type the formula 1500+1.05*tvdss_m.
  4. Under the Output Extents section, select a 3D survey.
  5. Enter the appropriate Inline and Crossline extents for the model, and select TVDSS as the output domain.
  6. The velocity model will appear in the Volume tab.
  7. In the Volume tab, double click the velocity volume or right-click and select Configure 'Volume'.
  8. Change the Class of the volume to Velocity (Interval) from the drop-down list.

Create a layered V0 model

  1. Create a Window Model using constants or horizons (see Creating a Window Model).
    Note: If you are creating a velocity model in depth, you must create a window model in depth.
  2. In the Process tab, click on the Add icon and select New Process.
  3. Create a Velocity Model (From Well Checkshots) process and type a Name for the process. Click OK.
  1. Select the Windowing Model that you have created.
  2. Under the Output Extents section, select a 3D survey.
  3. Enter the appropriate Inline and Crossline extents for the model.
  4. Under the Per-Layer Settings section, change the Calculation types to User-specified constant and enter an appropriate value in the adjacent box.