Hand Editing Contours to Influence a Surface Model

Hand Edited Contours

Computer aided mapping is a great tool for creating maps and surface models quickly. Advanced gridding algorithms can produce highly accurate surface models, but sometimes a geoscientist wants to have a direct influence over the final output.

Petrosys makes this easy by providing tools for the geoscientist to edit contours and utilize multiple data sources when creating a gridded surface. This walkthrough will teach you how to use Petrosys to hand edit contours created using normal workflows and then use those hand edited contours to influence a specific area within the gridded surface.

The tools we will use are the Contour Fault and Polygon (CFP) editing toolkit and a gridding operation called ‘Localised re-gridding’. All we need to perform this operation is a grid, a contour file, and a polygon.

Editing and Influencing the Overall Surface Model

Using the Petrosys mapping module, display the grid and contours that were previously created using Petrosys and zoom in on the area you want to change. Draw a polygon around the area using Edit/Create Single Polygon, this will later be used in the Localised re-gridding operation. You may want to hide the grid to make the editing process easier.

Choose Edit/Contours Faults and Polygons and select the contour file. Deselect the polygon and fault file selectors using the right mouse button and click OK. You should see the CFP editor toolbar appear. You can hover over the buttons to find out what each tool does (for more detail look at the help topic Map Data Editor). Modify the contours to your choosing. The final grid surface will reflect the structure of the edited contours. Once the contours look good, exit the editor by clicking the X icon and change the name of the contour file so you don’t overwrite the original file.

Move from the Petrosys mapping module to the Gridding and Contouring module. ChooseGrid/Create grid… Set the edited contour file as the only input and then switch to the methods tab. Change the Operation to Localised re-gridding. Now you can select the original grid file and the polygon within which you want to change the grid. Run the gridding process like you normally would.

Better Results Influenced by Knowledge and Experience

Now that you have a new grid and contours you can display them on a Petrosys map. Notice how the grid has only been modified within the polygon that you just created, but the rest of the grid has stayed the same.

This quick and easy process gives the geoscientist more control over the final model and allows Petrosys to utilize the knowledge and experience of the user in creating a more accurate surface model.