Our notion of reality in seismic interpretation and structural geology usually follows a series of careful observations and ideas that eventually crystallize into a best-case model. In most other branches of science the strength or reality of such models, or hypotheses, is increased by the number of robust tests that either refine or fail to disprove the original idea. However, geological models in the hydrocarbon exploration and production sector differ because the starting point for testing a hypothesis is usually an interpretation of seismic data or other remote measurements, rather than the direct observation of an effect.

The scientific method of prediction tested by observation is a key part of mapping three-dimensional (3-D) structures in the field and geological training. An analogous, rule-based approach also applies to the accurate creation of 3-D subsurface structural models. A defensible structural model must embody more than fault and horizon surfaces. It must also honor the rules of structural geology. Some simple rules are outlined in this chapter. These can be applied iteratively throughout the life of the seismic interpretation. Failure to honor structural rules leads to poor interpretations that may be compounded by a lack of appreciation of the importance of 3-D perspective. In this chapter, we also briefly explore the historical use and understanding of perspective.

Those in the exploration and production industry need to think carefully about how to leverage the 3-D interpretation and modeling process. Most importantly, since it is managers who control the exploration and production workflow, they above all need to be informed about the advantages of using a structurally qualified 3-D model in future projects.