Sv Principal Stresses

When preparing a wellbore stability analysis, using either the Advanced Stress or Wellbore Stability workflows, the SV Principal Stresses form (advanced stress & failure > Setup > Sv Principal Stresses or wellbore stability > Setup > Sv Principal Stresses) is used to specify and review the various stresses used for input in the stability calculation. If you have completed the 1D model workflow, these stresses will have already been calculated and you may select from these stresses to use as an input. If, however, you have not completed the  1d model workflow, or you have other stress data you wish to use for the workflow, you can import it and then make your selections.

Instead of selecting logs as the input data for the stresses, you can specify constant values to use for the stresses using the Advanced Mode form.

To specify the principal stresses

  1. On the Sv Principal Stresses form, use the drop-down lists to select the Pore Pressure and Overburden Stress. If carried over from the 1D model workflow, the calculated Shmin and SHmax logs are automatically selected and cannot be changed.
  2. Specify 'SHmax Azimuth' data using the drop-down list or check the use constant option to define a constant azimuth value to use during the calculation.
  3. Optionally, select a fracture gradient.
  4. Click OK to accept your selections and proceed to the Rock Properties form.
If you are using the Get Stress or Constrain Stress modules to calculate Rock Properties, you do not need to define them as input. If you have Rock Properties data available, you can use it to calibrate results from this module.