AN INTERACTIVE PROGRAMMING ENVIRONMENT FOR THE DEVELOPMENT OF EXPERT SYSTEMS IN WELL LOG ANALYSIS

Abstract

The job of a well log analyst is to infer properties of subsurface rock layers from measurements taken in a petroleum well bore. Although there are many FORTRAN programs for the numerical analysis and display of this data, log analysis also requires symbolic processing, and can benefit from the use of expert systems. This paper describes Interlog, an interactive programming environment designed to facilitate the development and use of expert systems in this field. Interlog provides interpreters for LISP, a FORTRAN-like language, and an object-oriented language; a screen editor and other programming tools; FORTRAN libraries for graphics and data storage; and libraries for the management and analysis of well log data. These tools can be used to build expert systems which contain modules written in various styles (e.g., procedural or object-oriented), and integrate symbolic and numeric processing. On the other hand, in order to be most useful to log analysts, these expert systems must run on currently used hardware configurations and utilize existing software and data. Therefore, while Interlog supports LISP, it is portable, can run under time-sharing systems, and can incorporate FORTRAN software. Because expert systems developed with Interlog can fit so tightly with current log analysis software, they should have immediate commercial uses.