I have some blank areas near the faults in my grid. How can I fix these holes in my grid for a more accurate volumetric computation?

grid_with_holes

Sometimes when you use faults in gridding, you may find areas in your grid, such as between narrow fault blocks, which are not filled with colour. This usually happens when the cell size of the grid is bigger than the fault block.

Re-gridding data at a smaller cell size may not always be suitable as it may introduce too much detail to the grid, or cause isolated anomalies to appear, thus creating a so called “bulls-eye” effect.

If you want the grid to remain unchanged while removing blank areas, the new grid editing tools in the Spatial Editor allow you to resample the grid and interpolate values onto the new grid nodes. The technique of resampling adds new nodes to a grid while honouring the original grid values.

Zoom into the blank area on your grid, Right Mouse Button (RMB) click on the grid in the display list and select Edit.

Double-click on the grid layer in the Spatial Editor and in the Values tab, turn on Display grid values.

edit_grid

RMB on the grid layer again and select Grid Definition. Reduce the cell size to a distance smaller than the blank gap in the grid.

edit_grid

Notice that new grid nodes have been added over the entire area of interest as well as inside the blank area of the grid. The grid nodes in the blank area, however, have no Z values. To assign Z values to these grid nodes, select the Interactively interpolate grid nodes without a value from surrounding cells option from the grid node editing tools and draw a polygon around the blank area.

interpolate_grid_nodes_button_1

polygon_around_blank_area

When you double-click to finish drawing the polygon, Petrosys will automatically start interpolating Z values. Once the previously blank area is colour filled, you can generate contours for this area by clicking on the Regenerate contours in areas where the grid has been modified icon. Don’t forget to save the changes before you leave the Spatial Editor!

regenerate_contours_button_2

interpolated_z_values

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