Abstract: This paper describes the process in which fault stress and its relation to tectonic fractures were analysed with fnite element method by establishment of mechanical model of Lower Permian carbonate based on the geologic characteristic of Lower Permian dens carbonate reservoir in othen Sichuan and theory of elastic mechanics, and case studies were made by taking some local structures, such as Yonganchang, as examples. Results were then compared to drilling data, which provide a new iea for quantitative study of fracture growth patterns in dense carbonate rock and prediction of gas reservoirs.

Key words: Dense carbonate rock, Fault, Fracture, Stress analysis, Gas reservoir