Pressure dependence of permeability in cracked rocks: experimental evidence of non-linear pore-pressure gradients from local measurements

 Pore pressure was measured locally in rocks exhibiting pressure-dependent permeability. We observed a transition from linear to nonlinear pore pressure distribution with increasing fluid pressure gradients. A new, micromechanics-based, analytical model was developed for the pressure dependence of permeability in microcracked rocks.