Validating markers

Use the Validate Marker form (Model > 3D Grid > Modify Grid > Grid Well Markers QC) to identify marker input that is not correctly honored in the grid. Such mismatches can be the result of missing markers or multiple wells going through a single grid cell with markers at different depths. With this form, you can identify and compute all mismatches, and resolve conflicting situations.

You can inspect mismatches in a number of different views. These views focus on a selected well and a selected horizon. Several filter options define the content of the views. Validity depends heavily on the well matching, which you should complete before creating the grid. If not, serious mismatches might be encountered. In this case, you should go back to the Depth Well Matching tool in the prepare> Post-Processing Tools strip or Well Matching in the Structural Modeling workflow and re-create the grid.

1. Select the grid.

   Select Grid  Select the grid that you want to validate.

   Top horizon  Select the top horizon of the interval you want to investigate.

   Base horizon  Select the base horizon of the interval you want to investigate.

2. Calculate wellbores with a mismatch.

   Create wellbore mismatch property  When you check this box, the calculated mismatches will be saved as a grid property in a new folder called 'Residuals', located in the JewelExplorer under 3D Grids > your 3D Grid > Properties.

   Calculate  Calculates the wellbores with mismatches. The resulting wellbores are listed in a 'Top Residual Table' view, which, together with other views, you can display in the next step. The content of the table can be further defined in Step 5.

3. In the View selection area, select the views to use for inspecting the calculated mismatches, and then click Update views at the bottom of the form. If you change the settings, the selected views are automatically updated. If you deselect a view, the view remains on the screen, but it is no longer automatically updated when you click Update views.

   If you are using a two-monitor setup, floating the views and placing them on the second screen allows you to more efficiently validate the markers in cases where you are using multiple views for the validation.

4. Use the following options to set the constraints for the results of the calculations.

   Maximum marker surface mismatch  Set a maximum allowed mismatch value. Wellbores in which mismatches larger than this value occur are considered as wellbores with mismatches. Wellbores in which no mismatches larger than this value occur are considered as ‘matched’.

   Threshold angle with horizontal well  This angle is the angle between the well trajectory and a stratigraphic surface at the intersection point. Wellbores that intersect a surface at an angle lower than the threshold angle are considered horizontal wellbores.

5. In Step 5 of the form, Wellbore selection settings, use the settings in the Wellbore selection in residual section to select the wellbores to show in the Tops Residual Table View.

   With mismatches  Select to show the data of all wellbores in which one or more mismatches occur.

   Matched wellbores  Select to show all matched wellbores, for example all wellbores in which no mismatches larger than the maximum mismatch set in Step 4 occur.

   Vertical wellbores  Select to show all vertical wellbores.

   Horizontal wellbores  Select to show all horizontal wellbores.

   In model data only  Select to show only the wellbores that belong to the model data.

6. Also in Step 5 of the form, use the settings in the Wellbores in 3D view section to select the wellbores to show in the updated 3D and Well Views (for the wellbore and horizon currently selected).

   Interfering wells  If selected, the Validate Marker: 3D View also shows wellbores that interfere with the wellbore selected in Step 6 of the form. Such wells can be sidetracks or relief wells or any other well whose trajectory intersects with that of the selected well. Interfering wellbores might cause a situation where wells enter the same grid cell with markers at different depths.

   Wellbores with marker in horizon  If selected, the Validate Marker: 3D View shows the wellbore selected in Step 6 of the form together with all wells that have a marker in the horizon selected in Step 6.

   Wellbores without marker in horizon  If selected, the Validate Marker: 3D View shows the wellbore selected in Step 6 of the form, together with all wells that have no marker in the horizon selected in Step 6.

7. In Step 6 of the form, select an Active wellbore and Active horizon to show in the currently selected views, and then click Update views.

Next steps

The workflow provides accurate information about markers that are not honored in the grid. Review the data, the tables and the 3D View and Well View. This analysis will give you an indication of any mismatches and how they can be adjusted. For instance, you can add missing markers in the Well View or shift a marker to resolve the problem of two wells entering the same grid cell with different markers.

When all conflicts have been resolved, re-create the grid, and then check the results again using the Validate marker form. The mismatches previously listed in the Top Residual Table should be resolved.