Input Definition

On the Input Definition form, you specify the data that is used for the analysis. The input is essentially the geomechanical model imported or created in the 1D MODEL workflow. To perform a slip analysis, the following data is required:

  • Principal stresses
  • Rock Properties
  • Fractures data

Principal Stresses

Currently, the Slip Analysis workflow supports vertical stress regime only.

Sv Principal Stresses  With the tab set to Sv Principal Stresses you can define the overburden stress (Sv), horizontal stresses (Shmin and SHmax), direction of maximum horizontal stress (SHmax Azimuth) and pore pressure as log or as constant. You can either import (using DATA strip) or calculate these logs in the 1D MODEL module.

Rock Properties

On the Rock Properties tab of the Input Definition form you can assign input data to be used for Biot Coefficient.

On this tab, you can also define the properties by selecting the <use rock types> option from the drop-down menu which uses the constant value from the Constants tab in the Validate Rock Types form.

Fractures Data

In the Fractures tab of the Input Definition form, users can enter data that defines the characteristics of fractures to be used in the analysis. This includes geometric properties such as dip and dip azimuth, which describe the orientation of the fractures. Additionally, users can specify calculation parameters including the sliding friction coefficient, cohesion, and the deviation limit for S3-normal fractures. These inputs are essential for ensuring accurate and reliable analysis results.

  • Sliding Friction Coefficient: default value of the coefficient of sliding friction of 0.6 to determine the threshold for critically stressed versus non-critically stressed fractures. You may modify this value by using a log data or by entering a new constant value. In general, the coefficient of sliding friction is between 0.6 and 1.0.
  • Cohesion: default Cohesion value is 0. You may modify this value by using a log data or by entering a new constant value. This parameter will affect the Mohr-Coulomb line in the Mohr Diagram.
  • Deviation limit for S3-normal fracture: this parameter is the maximum angle between the normal to a fracture plane and the minimum principal stress direction for which a fracture is considered to be a Mode I (tensile) fracture. If the deviation angle is below this limit, application considers that fracture normal to S3. The default deviation limit is 10°; you may modify this value by entering a new constant value.