Abstract：Expert system for seismic facies interpretation in continental fault basins is an intelligent interpretation tool that combines areal seismic stratigraphic theory with expert system principles. Seismic facies interpretation (sedimentary facies recovery) which is the essential of areal seismic stratigraphy involves some troubles:big data volume, many control factors, ambiguous interpretations and so on, An expert system, which acts as a real expert in the corresponding field, can make strict logic inference and draw reasoable conclusion of a complicated problem by using the rich knowledge and experience together with rigorous speciality theorems and regulations. This expert system is the explorative application of expert system to seismic facies interpretation. This expert system consists of a "shell"and a knowledge base. The shell includes three essential units: inference machine performing analysis and demonstration, user interface for information exchange between interpreter and the system, and the explanation module that describes inference procedure. The knowledge base stores up many informations: basin evolution stage, drilling lithological facies, seismic fades parameters, seismic facies pattern, depositional system and so forth. This expert system showed satisfactory function in interpreting seismic facies of north sag in Liaoxi depression in the Bohai Sea basin.
