5.3.3 Representation Level

The representation level corresponds to the 3D modeling expression of the feature initialized at the beginning (as described in Section 5.3.1 Feature Level ).

Often, a representation contains a topological description and very often the 3D position of the “indexable elements” of this topology. Additionally, it has more concepts for organizing its data; for more information about representation concepts (including indexable elements) see 6 Representations (Shared Concepts) .

NOTE: In RESCUE (predecessor to RESQML), software packages exchanged data only at the representation level. For example, in RESCUE, software only exchanged a grid representation and we did not know how and when it was modeled, nor the horizons and faults used to construct the grid. In RESQML v1.1, horizons and faults had features and interpretations.

With the RESQML knowledge hierarchy, a representation "knows" the UUID of the interpretation on which it was based (see 5.1 Features, Interpretations, Representations , and Properties ). With this information, a user can return to the last geomodeling process and build a new representation, based on the same principles as the previous one, but with different parameters. For example:

• Structural example: A user can use a triangulation to represent a horizon previously represented as a 2D grid. After more operations, he/she can come back to the original 2D grid information data for precise fitting purposes.
• Reservoir example: A user can create a new representation by executing a local grid refinement after having reduced the number of cells of an existing representation. The stratigraphic column attached remains the same.