Many offshore producing regions (and some onshore regions, such as Prudhoe Bay) are complicated by dual nemeses: intersecting non-vertical faults and directional well bores. Fault occurrences are observed in well bores or on seismic lines. When many fault occurrences are present, it often is difficult to determine which fault cuts are associated with which faults. An interactive contouring system allows the user to try various ways of connecting fault occurrences to form (intersecting) fault surfaces in (subsurface) space.

Once the faults have been modeled, the next task is to model (reconstruct, contour) subsurface formations as they interact with the various faults. This task is difficult enough when there are many formations and many faults. The task is even more difficult when directional wells are involved, since isopachs needed for reconstruction (i.e., stacking) are hard to determine.

A multi-surface multi-fault contouring system is being used to perform these complex subsurface analyses. A case study from offshore Gulf Coast illustrates its use.

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