Creating Synthetic Cases
Each row in the Synthetics table defines a synthetic seismic experiment. Each case has:
- an angle of incidence (for calculating reflectivity)
- a wavelet (for convolution with the calculated reflectivity) to generate the synthetic
- a seismic volume (for comparison and ties)
- In the Synthetics window, open the Synthetic tab.
- Click the Add Row icon (+) in the Angle Stacks section to add a synthetic case. The example shows four synthetic cases.
- Provide a name for each synthetic case. These names are used to identify the curves in the synthetics display as well as in well curve selection.
Enter the angle of incidence under the Angle° column.
- When tying to seismic stacks, use the midpoint of the angle stacking range. e.g. To tie a near stack of 5 to 15 degrees, use 10 degrees as the angle of incidence.
- Shear logs are required to calculate synthetics for angles greater than 0.
Select a wavelet to use for each synthetic case.
- Wavelets are created and managed in the Wavelet tab of the Control Panel.
- For a single synthetic case, the same wavelet is used at all wells. If necessary, the wavelet can be overridden for specific wells (see Overriding Wavelets).
- Important: Make sure your wavelet is appropriately scaled. A useful rule of thumb is to scale the wavelet to 10x the seismic peak amplitude. (see Creating a Wavelet).
For each case, select a seismic volume to tie / compare to.
- Synthetics supports only time-domain volumes. Use a Volume Resample process to convert depth volumes for use with synthetics.
- The synthetic case uses the same class as the selected seismic stack.
- If a value is entered for noise, seismic stack ± noise curves are calculated. Display these curves by enabling the Angle Stacks + Noise curve in the View tab (see Defining View Settings). This can be a useful QC measure.
Note: If your synthetics are not displaying correctly: