11.1.5 Advice on Grid Export

This section is intended to provide advice on aspects of grid export that experience has shown to be most variable from application to application. It is not an exhaustive list of important and useful grid features.

When exporting a grid, an application should especially preserve information that is difficult or impossible to reconstruct in the absence of the structural framework upon which a grid is often based.

• Include reference to the structural model interpretation from which the grid is derived.
• Export faults as grid connection set representations to support quantitative work, and export faults as a subrepresentation based on the pillars of a grid for qualitative work. (Stair-steps faults cannot be represented simply as pillars and are discussed in more detail, below.)
• Emphasize the use of “cell” and cell-face-pair “node” connection properties in preference to other property attachments.
• Take advantage of the parametric points because these include more information on the geometry of a grid than simply the position of the cell node vertices.
• For a grid with “layer gaps”, consider exporting a version of the grid with extra layers instead of gaps, because many geologic modeling applications do not support grids with such gaps.

• Take advantage of the redefined geometry representation, which allows one representation to be constructed from another. This may be used in a “belts and braces” approach to effectively export the geometry of a representation twice. For example, one representation may use the preferred description based on parametric points on spline curves to describe the coordinate lines of a grid, while another uses explicit (X,Y,Z) points. This ability should allow experimentation between different application vendors as the new standard comes into use.