Temperature and Confining Pressure Effects on the Permeability of Fractured Rocks

Permeability was measured in triaxial compression condition under confining pressures of 1–15 MPa at 295 K and 353 K on Shikotsu welded tuff, Kimachi sandstone, and Inada granite. At 295 K, the postcompression permeability of Shikotsu welded tuff became smaller than that before axial compression. The permeability of Kimachi sandstone was higher than that before axial compression under low confining pressures, but lower under higher confining pressures. On the other hand, the postcompression permeability of Inada granite was higher than that before axial compression regardless of the confining pressure values. At 353 K, the post-compression permeability was lower than at 295 K for all the rock types but not so obvious for Kimachi sandstone. Influence of confining pressure was less for Shikotsu welded tuff but more apparently for Inada granite than at 295 K. The reasons behind the permeability changes are discussed.