3-D Semi-Automated Fault Interpretation in CASI Using Evolving Surfaces

Benjamin J. Kadlec, Geoffrey A. Dorn, Jonathon Marbach, and Francis A. Coady
TerraSpark Geosciences, Boulder, CO

An adaptable 3D fault interpretation workflow that generates highly accurate surfaces is presented. The first step of the workflow generates an attribute that enhances fault discontinuities from a seismic volume. Next, seed points are generated either manually from a coarse handpicked fault region or automatically using a lineament extractor. An implicit surface is created from the seed points as an initial approximation to the faults. A fault segmentation algorithm then evolves the implicit surface, guided by the fault-enhanced attribute, into a dense planar representation of one or more faults. Classification techniques separate the planar representation into discrete surfaces based on dip and azimuth. The interpreter then uses an integrated 3D visualization technique to decide on a final interpretation by simple mouse strokes that merge the discrete surfaces into faults.

This technique addresses and overcomes limitations and pitfalls of similar methods. Results of this semi-automated approach are compared to a human interpretation in order to demonstrate accuracy and value.

Interactive techniques allow the interpreter to guide the generation of geologically meaningful faults that honor the structures represented in the seismic volume. Complex fault systems with intersecting and X-patterns are properly handled. The entire workflow is demonstrated as a case study in the Gulf of Mexico.

AAPG Search and Discovery Article #90078©2008 AAPG Annual Convention, San Antonio, Texas