Control Effect of Active Faults on Deep Confined Brine Mining Engendered, Mahai Salt Lake, Qaidam Basin

Abstract As shallow salt lake resources are increasingly exploited, deep confined brine has become a strategic alternative due to its widespread distribution and significant reserve potential. However, unfavorable reservoir characteristics, particularly low permeability and poor recovery efficiency, have historically rendered these deposits uneconomic, restricting their utilization. Taking the Mahai Salt Lake in the Qaidam Basin as a representative case, this study investigates the structural controls on brine enrichment through an integrated approach. Previous long‐term metallogenic studies and exploration data indicate occurrences of an extensional fault zone favorable for brine accumulation. Therefore, we applied InSAR deformation analysis to assess coseismic and postseismic surface responses. Combined with radon‐222 emanation mapping, our findings reveal a strong spatial correlation between high‐productivity brine boreholes and active fault systems. The existence of active faults enhance brine migration and storage, provided that the target reservoirs have substantial halite thickness and maintain relatively low clay‐silt content.