Assigning data to a fault model

Once the modeling parameters for the fault model have been defined (see Set Modeling Parameters) you can add faults (and/or unconformities and intrusions) to your fault model by assigning them from a prepared data source. When the source is a Surface Set, the surfaces you want to assign need to have a tri-mesh representation; when the source is a Seismic Interpretation, faults need to have a polyline set representation and unconformities/intrusions need to have a tri-mesh representation. Surfaces that do not have the required representation will not show up in the table on the Assign Data form.

In case want to assign faults, unconformities or intrusions and you don't have the necessary tri-mesh representations, you can create them as follows:

• Fault polyline sets (or point sets) in your Surface Set are triangulated as part of the Surface Sets workflow step Triangulate Faults (prepare > Surfaces > Triangulate Faults).
• Unconformities or intrusions in a Surface Set with a point set, polyline set or 2D grid representation can be interpolated and triangulated using the Create Surface workflow of the prepare > Surfaces strip (PREPARE > Surfaces > Create Surface).
• Unconformities with a 2D grid representation in your Surface Set can also be triangulated via the context menu. In the JewelExplorer, open the context menu of the 2D grid and select Create > Create Tri-mesh. The tri-mesh will be added to the event in the Surface Set, next to the 2D grid.
• Unconformities or intrusions in a Seismic Interpretation with a point set or polyline set representation can be triangulated with the Triangulate tool of the Post-Processing Tools strip (prepare > Post-Processing Tools > Polyline Set Tools > Triangulate).
• Unconformities with a 2D grid representation in a Seismic Interpretation can be triangulated via the context menu of the 2D grid. Right-click on the 2D grid in the JewelExplorer and select Create > Create Tri-mesh. The tri-mesh will be added to the event in the Seismic Interpretation, next to the 2D grid.

Note that you cannot mix and match data sources for your fault model; once you assigned faults to a fault model from a particular data source (e.g. Surface Set 1), you cannot assign faults from a different data source (e.g. Surface Set 2); selecting faults from a different source will reset the model and remove previously assigned faults. If you want to use surfaces from various sources it is recommended to first create a new surface set.

At the end of this workflow step, the assigned data will exist as tri-meshes (polyline sets are triangulated) in the fault model in the JewelExplorer.

To assign data to your fault model

1. Open the Assign Data form (model > Faults > Assign Data) and under Model, select the fault model to which you want assign faults (and unconformities/intrusion).
2. From the Source drop-down list, select the source that contains the surfaces that you want to assign. Upon selection, the table on the form will show all faults, unconformities or intrusions within that data source that have a 'valid' data representation, i.e:
• In a Surface Set, all faults, unconformities and intrusions must have a tri-mesh representation in order to show up in the table.
• In a Seismic Interpretation, faults must have a polyline set representation; unconformities and intrusions must have a tri-mesh representation in order to show-up in the table. When you click Apply or Next at the base of the form, the fault polyline sets will be triangulated according to the settings you entered on the prepare > Seismic > Triangulation Settings form.
3. From the Marker set drop-down list, select the marker set that contains fault markers you want to use to depth well match your faults.

4. From the Surfaces list, select the faults you want to assign to your fault model by checking the corresponding checkboxes.

   The Surfaces list

   • The Assigned column indicates whether the surface has already been assigned to the selected fault model.
   • The column named after the selected source displays the names of all surfaces within the source that have a 'valid' data representation.
   • The Length column gives the length of the fault. You can change the unit by opening the context menu of the column header; right-click on the column header and select Units, then choose your preferred unit.
   • The Type column indicates whether the event is a fault, intrusion or unconformity.
   • The representation column () indicates the existing geometric representations.
   • The Marker Set column indicates the name of your selected marker set; the next column indicates whether a fault marker exists in that set for any of the listed events.
   • You can open a context menu for each of the column headers by right-clicking on them; you can use filters, sort or change the layout of the columns.
5. Check the Resample faults automatically checkbox at the base of the form to resample tri-meshes according to the settings defined on the Set Modeling Parameters form (previous step in the Fault Modeling workflow, see Set Modeling Parameters). Resampling is recommended because the 'Solve Fault Intersections' step in the Fault Modeling workflow bases retraction and extension segments on the specified modeling parameters. Non-resampled fault tri-meshes can lead to sub-optimal preview and solving of fault intersections. Fault cutoff line editing is also steered by the modeling parameters. Resampling works as follows:
   • If the input is a tri-mesh (from a Surface Set) the tri-mehs gets resampled directly.
   • If the input is a polyline set (from a Seismic Interpretation), first the polyline set is triangulated (based on the triangulation settings specified in the Seismic Interpretation workflow) after which the generated tri-mesh is resampled according to the specified modeling parameters.
   If you do not check the box, the original surface will not be resampled and the original tri-mesh will remain unchanged.
6. Click Apply to assign the faults to the fault model and keep the Assign Data form open, or click OK to assign the faults and move on to the next step in creating your fault model, Depth Well Matching.