(n.) Reservoir Characterization. The study of ideas that enable computers to do the things that make people seem intelligent. The term is commonly abbreviated as A.I. Many computer programs written for use in the oil field utilize "rule based" approaches to provide expert systems. The rules are taken from an expert working in the field and are written in a way that attempts to reproduce the knowledge and approaches used by that expert to solve a range of real problems. Most such programs are limited to specific areas such as dipmeter interpretation, electrofacies determination, reservoir characterization, blowout prevention, drilling fluidselection, etc. Sometimes expert systems are written in computer languages that easily handle "rules" such as LISP, but once fully tested are usually translated to BASIC, C or FORTRAN to be compiled into efficient applications or programs. See: Neural Networks