ASTM D 4630:2019

1.1 This test method covers a field procedure for determining the transmissivity and storativity of geological formations having permeabilities lower than 10^-3 µm² (1 millidarcy) using constant head injection. 1.2 The transmissivity and storativity values determined by this test method provide a good approximation of the capacity of the zone of interest to transmit water, if the test intervals are representative of the entire zone and the surrounding rock is fully water-saturated. 1.3 Units- The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. Reporting of test results in units other than SI shall not be regarded as nonconformance with this standard. Note 1: Unit Conversions -The permeability of a formation is often expressed in terms of the unit darcy (non-SI). A porous medium has a permeability of 1 Darcy when a fluid of viscosity 1 cp (1 mPa·s) flows through it at a rate of 1 cm³/s (10^-6 m³/s)/1 cm² (10^-4 m²) cross-sectional area at a pressure differential of 1 atm (101.4 kPa)/1 cm (10 mm) of length. One Darcy corresponds to 0.987 µm². For water as the flowing fluid at 20°C, a hydraulic conductivity of 9.66 µm/s corresponds to a permeability of 1 Darcy. Permeabilities may also be expressed as millidarcy (md), which is not an SI unit. 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. 1.5 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use. 1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

07.060