Abstract:To elucidate the coupling evolution mechanism of argillization and permeability in fault fracture zone filling materials driven by reservoir water seepage pressure, research progress on geological characteristics, experimental methods, and degradation mechanisms was systematically reviewed. Under in-situ high tectonic stress constraints, compressible faults exhibit a “fault core-failure zone” zonal structure. The low-permeability barrier within the core, which is rich in clay minerals, is susceptible to mineral softening and argillization under prolonged seepage pressure, resulting in an increase in permeability by three to five orders of magnitude. In-situ high-pressure water injection tests can capture the inhibitive effect of tectonic stress on fracture closure. In contrast, traditional laboratory tests often fail to accurately simulate realistic seepage pathways due to weakened cementation effects and stress release-induced distortions. The argillization of clay minerals leads to pore reconstruction, while fine particle content significantly increases the initiation pressure gradient through mechanisms such as flocculation cementation and “water film” effects. Seepage pressure-driven degradation follows a pattern wherein water seepage pressure promotes the penetration of seepage channels by propagating original fractures and accelerating particle migration and loss, ultimately leading to a notable reduction in the critical hydraulic gradient.