ASTM D4525 – Standard Test Method for Permeability of Rocks by Flowing Air (Withdrawn 2022)
Description:
Significance and Use
5.1 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: The quality of the result produced by this standard is dependent on the competence of the personnel performing it, and the suitability of the equipment and facilities used. Agencies that meet the criteria of Practice D3740 are generally considered capable of competent and objective testing. Users of this standard are cautioned that compliance with Practice D3740 does not in itself assure reliable results. Reliable results depend on many factors; Practice D3740 provides a means of evaluating some of those factors.
Scope
1.1 This test method covers the determination of the coefficient of specific permeability for the flow of air through rocks. The method 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 9.869 × 10-18 m2 (0.01 millidarcy), and is limited to rocks free of oil or unctuous matter.
1.3 The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units are provided for information only and are not considered standard. Reporting of test results in units other than SI shall not be regarded as nonconformance with this test method.
1.4 All observed and calculated values shall conform to the guidelines for significant digits and rounding established in Practice D6026.
1.4.1 The procedures used to specify how data are collected/recorded or calculated, in this standard are regarded as the industry standard. In addition, they are representative of the significant digits that generally should be retained. The procedures used do not consider material variation, purpose for obtaining the data, special purpose studies, or any considerations for the user’s objectives; and it is common practice to increase or reduce significant digits of reported data to be commensurate with these considerations. It is beyond the scope of this standard to consider significant digits used in analytical methods for engineering design.
ASTM D4517