ABSTRACT: Fault seal risk analysis in "new" exploration plays

Handschy, James W., and Bradley D. Patton , Phillips Petroleum Company, Bartlesville, OK

Fault seal analysis is a powerful tool for predicting trap risk and volume retention potential where fault seals are required for a trap to be effective. Reliable, quantitative fault seal analysis techniques have been routinely applied in established plays since the 1960's. These techniques are typically analytical, grounded in empirical calibration, and require a significant amount of information about the geology of the potential fault trap being analyzed. This requirement for detailed knowledge of the geology at the prospect and at analog fields has generally restricted the perceived accuracy of fault trap analysis in "new" exploration plays where there is a large amount of uncertainty about the geology at the prospect and there are no analog fields. In these exploration settings traditional fault trap analysis techniques are usually underconstrained.

By compiling published and proprietary fault seal data from around the world and separating the individual contributing fault seal factors into geologically linked components, we have developed a hierarchical approach to fault seal analysis in "new" exploration plays. This approach utilizes detailed geologic and geophysical data where it is available and leverages geologically constrained statistics. It incorporates as much information as is available about the structural geology, the stratigraphy, the burial history, and the deformation history. Although the technique is probabilistic, it evolves from being mostly statistical to being more deterministic as new information is incorporated. Thus, as knowledge is added, the amount of uncertainty decreases, it converges with traditional fault seal analysis techniques, and the accuracy increases.

AAPG Search and Discovery Article #90913©2000 AAPG International Conference and Exhibition, Bali, Indonesia