Automated 3D geological consistency checking: a geomodelling tool

Abstract:

As 3D modelling workflows become more sophisticated, their output often results in a high number of different realizations. Often a significant number do not respect basic geological rules, even if they fit mathematical and geometrical constraints, requiring them to be checked before getting deeper involved into the following steps (e.g. flow or geophysical simulation) which can be expensive to run on a high number of models.

Another solution would be to integrate geological knowledge directly into modelling algorithms at run-time, but this is also currently very difficult without impacting the speed and the efficiency of the algorithms. Alternatively, the geological consistency of 3D models can be checked right after their construction, in order to detect as soon as possible inconsistent models.

Following this alternative approach, we developed a semi-automated tool in order to check the geological consistency of a given 3D model. First, the main geological principles are translated into matrices listing the validity of a given spatial relationship between two objects, by considering their nature, polarity and temporal relationship. Secondly, the input 3D model is explored in order to detect all the binary spatial relationships between any pair of objects. Then, by combining the spatial relationships observed with the corresponding temporal relationships, and the list of objects alongside their nature and polarity, the tool compares the results with the general geological rules matrices. Finally, the 3D model is declared consistent or non-consistent. If the model is declared non-valid, the information about where the inconsistency is sent back to the modelling algorithm to help improve future realizations.

In this presentation, we will explain the principles behind the consistency checker as well as demonstrate applications on synthetic and real case studies.