ABSTRACT: A New Paradigm for Prospect Appraisal

FANG, J. H., and H. C. CHEN, University of Alabama, Tuscaloosa, AL

The objective of prospect appraisal is to assess hydrocarbon potential in an exploration prospect. Despite the progress made in petroleum geology during the last decade, we geologists still don't have a complete understanding of geological processes that led to hydrocarbon accumulations. Thus, methods of quantitative prediction of hydrocarbon volume in a prospect are still in their trial stage. One of the reasons why a purely quantitative approach is still immature is the lack of formalism in dealing with impreciseness of measured data and incomplete information.

Conventional approaches focus on the use of numerical methods, such as probabilistic methods coupled with Monte Carlo simulations for hydrocarbon generation, migration, and accumulation. These methods presume the availability of voluminous statistical data and manage uncertainty through probability theory. In an attempt to circumvent the aforementioned shortcomings in the current practice of prospect appraisal, we herein propose a new paradigm based on a multicriteria decision-making model, which is rooted in fuzzy set theory. This technique considers all available information, which is usually fragmentary and imprecise--the kind of information that cannot be incorporated in the traditional methods.

In essence, this method employs fuzzy implications to gauge satisfaction levels associated with each measure of the characteristics associated with the source rock, migration, reservoir, trap, and seal. We have developed a computer program XPROS to implement our new approach. Case studies, which will be illustrated, gave encouraging results.

AAPG Search and Discovery Article #91012©1992 AAPG Annual Meeting, Calgary, Alberta, Canada, June 22-25, 1992 (2009)