Experimental study on the nonlinear flow characteristics of fractured granite after high-temperature cycling

Abstract To understand the influence of temperature on flow characteristics fractured granite, high-temperature cyclic thermal treatment and tests rock sample with different joint roughness coefficients intact samples were conducted. The larger confining pressure coefficient will increase resistance fluid affect fluid. With increasing, aperture fractures, number micro-fractures, micropores which forms a large new connected hydraulic channels in matrix. Forchheimer's law Izbash equation can well describe nonlinear characteristics, fitting are greater than 0.99. As increasing temperature, slope curve between volumetric rate gradient gradually decreases, decrease. transmissivity decrease Reynolds change range that temperature. When is at lower level ( T = 200 ~ 600 °C), contribution split fracture to permeability continuously increases 800 °C, matrix rises then exceeds fracture. results indicate 400 °C critical after granite cycling more obviously.