ASTM D4525-08

This test method is designed to measure the permeability to air of a small sample of rock. By extrapolation, this test method also determines an equivalent of the liquid permeability. This parameter is used to calculate the flow through rock of fluids subjected to a pressure differential.

Note 1—Notwithstanding the statements on precision and bias contained in this test method, the measures of precision of this test method is dependent on the competence of the personnel performing them, and on the suitability of the equipment and facilities used. Agencies that meet the criteria of Practice D 3740 are generally considered capable of competent and objective testing. Users of this test method are cautioned that compliance with Practice D 3740 does not in itself assure reliable testing. Reliable testing depends on many factors; Practice D 3740 provides a means for evaluating some of those factors.

1.1 This test method covers the determination of the coefficient of specific permeability for the flow of air through rocks. The procedure establishes representative values of the coefficient of permeability of rocks or well-indurated soils.

1.2 This test method is limited to permeability values greater than 0.9869 pm² (1.0 picodarcy), and is limited to rocks free of oil or unctuous matter.

1.3 The values stated in SI units are to be regarded as the standard. The values given in parentheses are mathematical conversions to inch-pound units that are provided for information only and are not considered standard.

1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.