CHEN, H.C., LILY LI, and J.H. FANG, Univ. of Alabama, Tuscaloosa, AL

ABSTRACT: Evaluation and Ranking of Multiple Prospects Using Fuzzy Logic

Assessment of a group of prospects may be carried out in two steps. In the first step, the assessor evaluates each prospect individually and separately, based on geological and geophysical data. In the second step, the assessor ranks the prospects using additional criteria of economic considerations.

The first step may be carried out in one of two ways: (1) employ a computer simulation of geological processes -- hydrocarbon generation and migration, trapping and retention, and recovery, or (2) use a new approach proposed by the authors (presented at the 1992 AAPG Convention) which makes use of fuzzy set theory. This paper addresses the second step of ranking the various prospects.

Both steps involve multi-criteria decision making, however, the first step is concerned with importance of the criteria and the second step evaluates priority, in terms of nongeological considerations, such as availability of acreage, location of the prospect, tax laws, environmental impacts etc. These are called second-order criteria by which we mean those criteria that we would like to have satisfied by our solution if they don't interfere with our getting satisfaction to the geological/ geophysical criteria.

We will show an example in which four prospects, which have all been found to be "good," are ranked based on the second-order criteria. This proposed approach is preferable to some sophisticated, and costly, economic analysis.

AAPG Search and Discovery Article #90987©1993 AAPG Annual Convention, New Orleans, Louisiana, April 25-28, 1993.