Designation:D4630−19StandardTestMethodforDeterminingTransmissivityandStorageCoefficientofLow-PermeabilityRocksbyInSituMeasurementsUsingtheConstantHeadInjectionTest1ThisstandardisissuedunderthefixeddesignationD4630;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope*1.1Thistestmethodcoversafieldprocedurefordetermin-ingthetransmissivityandstorativityofgeologicalformationshavingpermeabilitieslowerthan10−3µm2(1millidarcy)usingconstantheadinjection.1.2Thetransmissivityandstorativityvaluesdeterminedbythistestmethodprovideagoodapproximationofthecapacityofthezoneofinteresttotransmitwater,ifthetestintervalsarerepresentativeoftheentirezoneandthesurroundingrockisfullywater-saturated.1.3Units—ThevaluesstatedinSIunitsaretoberegardedasstandard.Nootherunitsofmeasurementareincludedinthisstandard.ReportingoftestresultsinunitsotherthanSIshallnotberegardedasnonconformancewiththisstandard.NOTE1—UnitConversions—Thepermeabilityofaformationisoftenexpressedintermsoftheunitdarcy(non-SI).Aporousmediumhasapermeabilityof1Darcywhenafluidofviscosity1cp(1mPa·s)flowsthroughitatarateof1cm3/s(10–6m3/s)/1cm2(10–4m2)cross-sectionalareaatapressuredifferentialof1atm(101.4kPa)/1cm(10mm)oflength.OneDarcycorrespondsto0.987µm2.Forwaterastheflowingfluidat20°C,ahydraulicconductivityof9.66µm/scorrespondstoapermeabilityof1Darcy.Permeabilitiesmayalsobeexpressedasmillidarcy(md),whichisnotanSIunit.1.4AllobservedandcalculatedvaluesshallconformtotheguidelinesforsignificantdigitsandroundingestablishedinPracticeD6026.1.4.1Theproceduresusedtospecifyhowdataarecollected/recordedorcalculated,inthisstandardareregardedastheindustrystandard.Inaddition,theyarerepresentativeofthesignificantdigitsthatgenerallyshouldberetained.Theproce-duresuseddonotconsidermaterialvariation,purposeforobtainingthedata,spe...
