This study investigates the influence of mineral composition, particularly clay content, on the Rate-State Friction (RSF) parameters (a, b, D_c) and induced seismic risk in the Longmaxi Shale Formation (Sichuan Basin, China). Through velocity-step experiments under simulated reservoir conditions (high temperature/pressure), the research quantifies how clay content (ranging 10–45 wt.%) controls fault stability. Key findings reveal that higher clay content promotes velocity-strengthening behavior (a – b > 0) by decreasing the evolution effect parameter b. The increasing critical slip distance D_c can limite the critical stiffness (k_cr) and suppressing seismic nucleation. These results provide a mineralogical framework for assessing seismic hazards during shale gas operations. The content of clay minerals can be one of the evaluation indexes in high-risk areas of induced seismicity.

Sichuan Basin,Shale gas,Induced seismicity,RSF theory