Oil-Well Data Interpretation Using Expert System and Pattern Recognition Technique

Abstract

This paper describes a program for interpretation of oil-well measurements. Two techniques have been merged for this purpose: the expert system technique (production rules) which lends itself to the symbolic reasoning aspect of the problem and pattern recognition technique (mainly the split and merge algorithm) to interpret curves measuring physical properties of rocks. Part of the knowledge of an expert in geology has been coded into 500 production rules together with hierarchy trees (such as petrography, paleontology) which allow the program an access to the rules containing assertions more general than the input data. There are two geological laws underlying the design of the program: (1) All sources of data are accounted for whenever they are available, (2) A description of a rock has no significance out of its context, which means that the identification of rocks must be guided by the knowledge of the environmental conditions. A session with LITHO is partially displayed.