Abstract: In this paper, the permeability values of 13 rock samples with different confining pressures are tested. The experimental results show that applied confining pressure of 1.5 MPa is enough to seal the rock samples; there is a falling trend of permeability values from the same rock sample with an average decline up to 26.27% when the confining pressures are within the upper and lower limit of industry-standards suggested pressures; permeability decreasing amplitude is related to the original permeability of rock samples, the effect of confining pressure on high-permeability rock samples can be ignored, but that on low-permeability ones is obvious, and the errors should be considered when using these data; permeability decreasing amplitude is independent of lithology.

Key words: permeability, measurement, confining pressure, lithology