Transient surface permeability test: Experimental results and numerical interpretation

Hydraulic pulse tests have been widely used to estimate the fluid transport properties of low-permeability geomaterials. This paper applies transient pulse test to measure the surface permeability characteristics of saturated Stanstead Granite cylinder. The proposed method makes use of a specially designed permeameter to generate hydraulic pulses within the sealed cavity. The cavity pressure is then allowed to dissipate as the fluid migrates into the saturated rock matrix. Crucial to interpreting permeability from transient surface permeability test is the influence of entrapped air bubbles within the pressurized cavity. The modelling results indicate that the air inclusions can significantly increase the fluid compressibility and thus delay the hydraulic pulse decay process, which may lead to underestimation of permeability.