Constructing surfaces

With the Construct Surfaces form (model > 3D Structure > Construct Surfaces) you execute the operation that will construct triangulated horizon surfaces based on the input data as assigned in the Assign Data step and the settings as defined on the Edit Model form. While constructing the surfaces, a QC 3D grid is built from which the surfaces are derived. This QC grid is placed under the 3D Grids item in the JewelExplorer and carries its own symbol ( ). The grid can be used for preliminary QC.

To generate the surfaces

1. Select the structural model for which you want to construct surfaces. You can hover over the factsheet icon () next to the drop-down list to review information about the model, such as the selected stratigraphic model and level and the associated fault model.
2. Create watertight surfaces When you check the box, the application attempts to create watertight connections between the (to be) constructed horizon surfaces and discontinuity surfaces (faults, unconformities and intrusions) from the fault model (see Definition of watertight and associated surfaces). It is recommended to use this option as watertight models are generally preferred over models with gaps between surface connections, even when these gaps are small. By default the checkbox is checked when opening the form for the first time for a structural model; after that, it will remember the last applied state.
   • For more about creating watertight surfaces, see Background to watertight surfaces.
   • For more about potential warning messages in the Output Information pane (Workspace > Panes > Output Information) see Warnings on watertightness in the Output Information pane.
Any existing fault cutoff line edits that you made with the Fault Cutoff Line Edits form, will be incorporated in the surface construction.
3. Click OK to construct the surfaces. Once constructed, the (triangulated) surfaces are available in the JewelExplorer under the structural model. For more info, see Visual QC of (re)constructed surfaces.
In case you have existing fault traces generated with the Create Fault Traces form, these will be automatically updated.

When the surfaces are constructed:

• a QC grid is generated and placed under the 3D Grids item in the JewelExplorer. It carries the name of the structural model, with the suffix '(QC)' added. A QC grid can be helpful to locate geometrical conflicts, such as faults sticking through another fault, gaps at fault intersections, etc. Geometrical conflicts are often more easily recognized in the grid than on the constructed surfaces themselves (see Troubleshooting artifacts for more details). In addition to aiding you in refining your model, the QC grid is also used to optimize performance as it stores data of the processing steps. You can delete the QC grid if you want to minimize the size of your solution, as the grid will be generated upon running Construct Surfaces again.
• the 'Collapsed Surfaces_Clean-Up' property is created under each surface in the JewelExplorer. This property indicates which parts of the surface collapse onto another surface and which not. The collapsed parts correspond to a value of '0' and are set to inactive, while the non-collapsed parts correspond to a value of '1' and stay active. The collapsed inactive parts will not be used as input data in the 3D Gridding workflow, to prevent artifacts from being introduced in some rare cases. Use this property when a surface truncates onto another surface in order to QC the collapsed parts that will be excluded. If you want to include the inactive parts, right-mouse click on the property in the JewelExplorer and select Delete. This way the entire surface will serve as input to the 3D Grid in the next workflow.

In case you want to stop the process during the actual construction of the surfaces, you can use the Cancel button in the bottom bar of the application.