Abstract: Computer Mapping to Test Multiple Contouring Hypotheses

Tarek Y. Ghazi, Peter R. Rose

Variation in contour mapping represents the most important component of uncertainty in estimating the value of exploration prospects. Given identical datasets, different interpreters draw different maps. Examples are shown, which illustrate the pronounced differences among many interpreters employing different mapping styles and hypotheses.

Perhaps the ideal way to estimate mapping uncertainty would be to employ several interpreters to independently map each prospect. This would obviously be impractical, especially in the midst of a downsizing industry, where manpower is short. Instead, computer-based methods are presented, to help the individual interpreter explore more contouring possibilities in less time.

Using already published computer mapping methods, the interpreter can vary the direction and magnitude of directional bias in contouring patterns. Other combinations of computer tools can handle more extreme geological hypotheses. The computer also enables the interpreter to overlay these different map versions to display a wider range of prospect size and shape than any single map might reveal. Charting the lognormal distribution of prospect area further quantifies the broader range of mapping uncertainty that these computer-based methods capture.

AAPG Search and Discovery Article #90986©1994 AAPG Annual Convention, Denver, Colorado, June 12-15, 1994