Assigning the area

On the Assign Area form (model > 3D Grid) you need to select an area. The area laterally constrains the 3D grid and also determines the lateral grid cell size (called step length 'I' and 'J' on the Create Area form which opens when you click on the green plus icon ). The highest quality 3D grid can be achieved by making sure the area is in line with the orientation and step length of the modeling parameters used during the construction of the Structural Model. You can select an existing area or create a new one and derive the parameters (origin, dimension, step length) from your input Structural Model.

On the Assign Area form, you can also specify to use a boundary during construction of your 3D grid. It is generally recommended to select the same boundary as was used during construction of your Structural Model (if you used one). You can also select no boundary or another boundary. The main purpose of selecting another boundary is to create a 3D Grid over a smaller area ('subset') of the Structural Model. Make sure you are aware of the implications of selecting no boundary or another boundary, see section Using the boundary on the Assign Area form (3D Gridding workflow).

To assign the area and select a boundary

  1. From the Area drop-down list, either select an existing area or click the green plus icon to create a new area. When you click the icon, the 'Create Area' form opens (see Create Area and follow the steps under 'To create an area').
    2. When you create a new area for your 3D Grid, the highest quality 3D Grid is achieved when the area's orientation and step length correspond with the modeling parameters of your Structural Model. To derive these parameters, select your Structural Model in Step 3 of 'To create an area' in topic Create Area.
  2. In the Boundary section on the form you can select to use/not use a boundary. For general information about boundaries, see Boundaries and Feature Sets. There are three options:
    • Structural Model - By selecting this option the same boundary is used as during construction of the Structural Model (recommended option). Upon selection (and for information purposes only) the name of the input Structural Model and used boundary appear on the form in the Source and Boundary drop-down boxes respectively. Note that if the Boundary drop-down box stays empty (no boundary name appears) this means that you did not use a boundary during construction of the input Structural Model and as such, no boundary will be used during construction of the 3D Grid.
    • Other Boundaries - With this option you can select another boundary with the purpose to create a 3D Grid over a smaller area ('subset') of the Structural Model (your boundary should preferably never extend beyond the edges of your input Structural Model). To select the boundary, first select the folder that contains the boundary (either 'Imports' or 'Data'). Then select the boundary from the Boundary drop-down list, which lists all boundaries within the selected source.
    • None - When you select 'None', no boundary is used while constructing the 3D Grid. Be aware that there can be implications to the lateral extent of the 3D Grid, especially when you used a boundary in combination with an unconformity assigned to the fault model during construction of the Structural Model, see Using the boundary on the Assign Area form (3D Gridding workflow).
  3. Click OK to assign the area and boundary and proceed to the last step in creating your 3D grid -Constructing a JewelGrid, or click Apply to assign the area and boundary while keeping the form open.