Porosity Estimation of a Reservoir Using Geophysical Well Logs and an Interval Type-2 Fuzzy Logic System

摘要

The authors propose a novel interval type-2 fuzzy logic structure that uses the advantages of type-2 fuzzy sets to estimate the formation porosity of the reservoir using geophysical well logs. The proposed system is constructed on the base of a set of fuzzy rules that includes type-2 fuzzy sets in the antecedent part and type-1 interval representing the centroid of a type-2 fuzzy interval in the consequent part of the rules. For structure identification, a fuzzy clustering algorithm is implemented to generate the rules automatically and for parameter adjustment the back propagation algorithm is used. To demonstrate the superiority of the proposed model, the results of the proposed type-2 fuzzy logic structure are compared with its type-1 counterpart.