1、Designation:D4525131Standard Test Method forPermeability of Rocks by Flowing Air1This standard is issued under the fixed designation D4525;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parenthe
2、ses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1NOTEEditorial corrections were made throughout in February 2014.1.Scope*1.1 This test method covers the determination of the coef-ficient of specific permeability for
3、the flow of air throughrocks.The method establishes representative values of thecoefficient of permeability of rocks or well-indurated soils.1.2 This test method is limited to permeability valuesgreater than 9.869 10-18m2(0.01 millidarcy),and is limitedto rocks free of oil or unctuous matter.1.3 Uni
4、tsThe values stated in SI units are to be regardedas the standard.The values given in parentheses are mathemati-cal conversions to inch-pound units that are provided forinformation only and are not considered standard.Reporting oftest results in units other than SI shall not be regarded asnonconform
5、ance with this test method.1.4 All observed and calculated values shall conform to theguidelines for significant digits and rounding established inPractice D6026.1.4.1 The procedures used to specify how data are collected/recorded or calculated,in this standard are regarded as theindustry standard.I
6、n addition,they are representative of thesignificant digits that generally should be retained.The proce-dures used do not consider material variation,purpose forobtaining the data,special purpose studies,or any consider-ations for the users objectives;and it is common practice toincrease or reduce s
7、ignificant digits of reported data to becommensurate with these considerations.It is beyond the scopeof this standard to consider significant digits used in analyticalmethods for engineering design.1.5 This standard does not purport to address all of thesafety concerns,if any,associated with its use
8、.It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2D653 Terminology Relating to Soil,Rock,and ContainedFluidsD3740 Practice for M
9、inimum Requirements for AgenciesEngaged in Testing and/or Inspection of Soil and Rock asUsed in Engineering Design and ConstructionD6026 Practice for Using Significant Digits in GeotechnicalData2.2American Petroleum Institute Standard:3RP-40 Recommended Practice for Core Analysis Procedure3.Terminol
10、ogy3.1 DefinitionsFor definitions of common technical termsin this standard,refer to Terminology D653.4.Summary of Test Method4.1 The permeability of a rock sample is measured byflowing dry air through the specimen and measuring theabsolute pressure,the flow rate,and absolute pressure differ-ential
11、of the air.Three or more tests are performed on a sampleat different mean air pressure values.The permeability valuesare plotted as a function of the reciprocal mean absolutepressure;those points lying on a straight line are extrapolatedto a value corresponding to an infinite mean air pressure toobt
12、ain an equivalent permeability value for liquids.5.Significance and Use5.1 This test method is designed to measure the permeabil-ity to air of a small sample of rock.By extrapolation,this testmethod also determines an equivalent of the liquid permeabil-ity.This parameter is used to calculate the flo
13、w through rock offluids subjected to a pressure differential.NOTE1The quality of the result produced by this standard isdependent on the competence of the personnel performing it,and the1This test method is under the jurisdiction ofASTM Committee D18 on Soil andRock and is the direct responsibility
14、of Subcommittee D18.12 on Rock Mechanics.Current edition approved Nov.1,2013.Published December 2013.Originallyapproved in 1985.Last previous edition approved in 2008 as D4525 08.DOI:10.1520/D4525-13E01.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Servic
15、e at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.3Available from American Petroleum Institute(API),1220 L.St.,NW,Washington,DC 20005-4070,http:/www.api.org.*A Summary of Changes section appears at the end of this
16、 standardCopyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 suitability of the equipment and facilities used.Agencies that meet thecriteria of Practice D3740 are generally considered capable of competentand objective testing.Users of this standard are cautioned that compliancewith Practice D3740 does not in itself assure reliable results.Reliableresults depend on many factors;Practice D3740 provides a means ofevaluating some of those fac
