Build Deck

The Build Deck form can be used to write a full deck for simulation with FLAC3D™. The expected input is a 3D mesh populated with appropriate geomechanical properties and pore pressure. The 3D mesh needs to consist of first order tetrahedrons, with or without discontinuous properties (split compartments). Geomechanical properties can be defined and populated using the geomechanical modeling workflow (MODEL > Geomechanics > Modeling) and the Output to 3D Mesh tool (MODEL > Geomechanics > Output Model > Output to 3D Mesh). Dynamic pore pressure can be mapped from a reservoir simulation result on a 3D grid and can be integrated with a background pore pressure using the Create Pore Pressure tool.

To build a FLAC3D deck

  1. Open the Build Deck form.
  2. Select a 3D mesh from the drop-down list. This has to be a first order tetrahedron mesh, with or without discontinuous properties (split compartments), and without split surfaces, otherwise it will not be accepted upon pressing Apply or OK.
  3. Select the following properties to provide input to the geomechanical simulation. All properties are filtered on the expected property type and storage type (auto-selected if only a single valid property is available), and need to have valid values in the entire model:
    4. Parameter Storage type Comments
    Young’s modulus Element  
    Poisson’s ratio Element  
    Density Element  
    Pore Pressure

    Node

    or

    Element

    		 Pore Pressure can be defined on nodes or elements, depending on the setting for pore pressure storage type. This should be a dynamic pore pressure, containing pore pressure changes over time. This property controls the timesteps that will be simulated. If dynamic pore pressure is only available in part of the model, ensure to provide valid values everywhere by integrating the dynamic pore pressure with a background pore pressure using the Create Pore Pressure tool.
    Azimuth of maximum horizontal stress Element  
    Effective maximum horizontal stress ratio Element  
    Effective minimum horizontal stress ratio Element  
    Water load Node (Optional) The water load property is only defined on the top surface, i.e., the top nodes of the model.
  4. Select a Deck folder to which the simulation deck will be written.
  5. Click Apply or OK. When valid input data is provided, a deck will be written to the selected deck folder. This contains:
    • A .f3grid file containing the geometry of the mesh
    • Several .txt files containing the selected property information, including one file per time step for the pore pressure
    • ImportExportFunctions.fis which contains assisting code for import/export in FLAC3D’s internal scripting language FISH
    • Run_model.dat which contains all simulation information and settings and can be run in FLAC3D

After closing and reopening the form, the previous settings are not retained. However, the previously used settings can be restored by opening the form from the Audit Trail (Home > Audit Trail > Open). For more on the Audit Trail, see Using the audit trail.