Synthetics (Stack & Gather)

Description Generate synthetic  or gather synthetic.
Module(s) Quantitative Interpretation, Explorationist *
Requirements
Related
Works with Stacks, Gathers

* This process is made available in the Explorationist module temporarily.

Generate stack (single angle), and angle gather, synthetics.

  1. In the Control Panel, go to View > New Single Well View.
  2. In the Single Well window, open the Process tab.
  3. At the tab header, click the blue "+" icon.
  4. Click on Synthetics.
  5. Type a name for the process and click OK.

Configuring Reflectivity

  1. Synthetic type to create: Stack or Gather.
  2. Reflectivity: Select the reflectivity to use.
    • Use existing reflectivity curve: If this option is chosen then the reflectivity curve will be used to convolve with a wavelet to generate a synthetic trace.
    • Calculate from elastic logs: If this option is chosen then the elastic log will be used to first generate a reflectivity curve, and then convolve the reflectivity with a wavelet.
  3. Click the blue "+" icon to add a new row or click the red "x" icon to remove the selected row.

If Use existing curve is selected:

  1. Type a name for the synthetic case. This name is used to identify the output curves.
  2. Angle:
    • For Stack Synthetic: Angle is not used in the calculation. It is only used for the output curve name.
    • For Gather Synthetic: Angle range and step must be the same as the reflectivity curve. The chosen wavelet is convolved with each angle of the reflectivity curve as specified in the range and step. The angle range values are inclusive, the order must be continuous and the range must be a multiple of the increment. Example, for a reflectivity curve generated for angle range 0-60 with angle step of 10:
      • Angle 0-10[10] - reflectivity at angle 0 and 10 are convolved with wavelet A.
      • Angle 20-40[10] - the start (20) is one increment (10) larger than the end (10) of the previous angle range.
      • Angle 50-60[10] - the start (50) is one increment (10) larger than the end end (40) of the previous angle range.
  3. Wavelet: Wavelet (for convolution with the input reflectivity curve) to generate the synthetic.
  4. Reflectivity: Select the Reflectivity Curve.
  5. Noise: If a value is entered for noise, synthetic ± noise curves are calculated.

If Calculated from log is selected:

  1. Elastic logs: Select the Vp, Vs and density curves.
  2. Type a name for the synthetic case. This name is used to identify the output curves.
  3. Angle:
    • Stack Synthetic: Angle of incidence for reflectivity calculation.
    • Gather Synthetic: Angle of incidence range and step for reflectivity calculation. The angle range values are inclusive, the order must be continuous and the range must be a multiple of the increment.
  4. Wavelet: Select the wavelet (for convolution with the input reflectivity curve) to generate the synthetic.
  5. Noise: If a value is entered for noise, synthetic ± noise curves are calculated.

Output

  1. Default output curve name:
    • For Stack Synthetic: Syn: [Process Name]_Stack_[Use Existing Curve / Calculated From Log]_Wellprocess_[name]_[angle]_Noise_[noise value]
      • For example: "Syn: Synthetics_Stack_UseExistingCurve_WellProcess_Near_10_Noise_0"
    • For Gather Synthetic: Syn: [Process Name]_Gather_[Use Existing Curve / Calculated From Log]_WellProcess_Noise_[noise value]_[angle range]
      • For example: "Syn: Synthetics_Gather_UseExistingCurve_WellProcess_Noise_10_0-50"
  2. Default output curve class:
    • For Stack Synthetic: Stack
    • For Gather Synthetic: Seismic gather
  3. Enable custom name: Enable user to define the output curve Process Name.
  4. Prefix: Text appended to the name of each output curve.
  5. Extent: Output is always in TWT.
    • Enter the start and stop time.
  6. Reset: automatically set the start and stop value to match the data in the first curve