Based on artificial intelligence research, the frame based system for reasoning described in this paper is one of the components of an intelligent decision support system for an information system on petroleum resources and use which is being designed by the Information Methodology Research Project as the first step in the development of a comprehensive intelligent information system for dealing with energy resources in the United States. By extending the notion of frames to include rule frames which can then be interpreted and applied, expertise of various kinds can be directly encoded into the frame representation. Frame based rules are useful in encoding constraints, performing actions, noticing complex situations, and deducing solutions. By varying the interpretation of a rule frame, the same competence knowledge can be used in performing each of these tasks. Rules are able to use frame based representation in finding other rules, avoiding most pattern-directed invocation. (Author/RAA)