Directionless analysis

Directionless analysis (model > Fault Stability > Directionless Analysis) enables you to analyze fracture stability by computing a directionless Tau Ratio. The directionless calculation picks the worst possible orientation with respect to the stress field. The conservative nature of this analysis allows you to evaluate the risk for activating fractures and faults that are not captured in the model or are not accurately represented. One advantage of this type of analysis is that you can analyze volumes that have no fracture representations.

To calculate directionless properties

1. Select the 3D mesh for which you want to perform the directionless analysis.
2. Select whether to use node or element 3D mesh properties for the pore pressure and principal stress input.
3. For PP, SP1, and SP3, select the pore pressure and principal stress properties.
4. For the Fault friction coefficient, enter a value.

5. Check the boxes for the undirectional values that you want to calculate:

   • Undirectional Tau Ratio
   • Undirectional CFF
   • Undirectional IPcrit
6. Click OK or Apply to perform the analysis.