ASTM D4630-2019 Standard Test Method for Determining Transmissivity and Storage Coefficient of Low-Permeability Rocks by In Situ Measurements Using the Constant.pdf

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1、Designation: D4630 19Standard Test Method forDetermining Transmissivity and Storage Coefficient of Low-Permeability Rocks by In Situ Measurements Using theConstant Head Injection Test1This standard is issued under the fixed designation D4630; the number immediately following the designation indicate

2、s the year oforiginal adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This test method covers a field procedure for

3、 determin-ing the transmissivity and storativity of geological formationshaving permeabilities lower than 103m2(1 millidarcy) usingconstant head injection.1.2 The transmissivity and storativity values determined bythis test method provide a good approximation of the capacityof the zone of interest t

4、o transmit water, if the test intervals arerepresentative of the entire zone and the surrounding rock isfully water-saturated.1.3 UnitsThe values stated in SI units are to be regardedas standard. No other units of measurement are included in thisstandard. Reporting of test results in units other tha

5、n SI shallnot be regarded as nonconformance with this standard.NOTE 1Unit ConversionsThe permeability of a formation is oftenexpressed in terms of the unit darcy (non-SI). A porous medium has apermeability of 1 Darcy when a fluid of viscosity 1 cp (1 mPas) flowsthrough it at a rate of 1 cm3/s (106m3

6、/s)/1 cm2(104m2) cross-sectionalarea at a pressure differential of 1 atm (101.4 kPa)/1 cm (10 mm) oflength. One Darcy corresponds to 0.987 m2. For water as the flowingfluid at 20C, a hydraulic conductivity of 9.66 m/s corresponds to apermeability of 1 Darcy. Permeabilities may also be expressed asmi

7、llidarcy (md), which is not an SI unit.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 theindust

8、ry standard. In 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 to

9、increase or reduce significant 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,

10、associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety, health, and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.6 This international standard was developed in accor-dance with internationall

11、y recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2D653 Terminolo

12、gy Relating to Soil, Rock, and ContainedFluidsD3740 Practice for Minimum Requirements for AgenciesEngaged in Testing and/or Inspection of Soil and Rock asUsed in Engineering Design and ConstructionD5717 Guide for Design of Ground-Water Monitoring Sys-tems in Karst and Fractured-Rock Aquifers (Withdr

13、awn2005)3D6026 Practice for Using Significant Digits in GeotechnicalData3. Terminology3.1 Definitions:3.1.1 For definitions of common technical terms used in thistest standard, refer to Terminology D653.3.2 Symbols:3.2.1 Cbbulk rock compressibility (M1LT2).1This test method is under the jurisdiction

14、 ofASTM Committee D18 on Soil andRock and is the direct responsibility of Subcommittee D18.21 on Groundwater andVadose Zone Investigations.Current edition approved Feb. 1, 2019. Published February 2019. Originallyapproved in 1986. Last previous edition approved in 2008 as D4630 96(2008),which was wi

15、thdrawn March 2017 and reinstated in February 2019. DOI: 10.1520/D4630-19.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe

16、ASTM website.3The last approved version of this historical standard is referenced onwww.astm.org.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standa

17、rd was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.13.2.2 C

18、wcompressibility of water (M1LT2).3.2.3 Gdimensionless function.3.2.4 Khydraulic conductivity (LT1).3.2.4.1 DiscussionThe use of symbol K for the termhydraulic conductivity is the predominant usage in groundwa-ter literature by hydrogeologists, whereas the symbol k iscommonly used for this term in t

19、he rock and soil mechanicsand soil science literature.3.2.5 Pexcess test hole pressure (ML1T2).3.2.6 Qexcess water flow rate (L3T1).3.2.7 Qomaximum excess water flow rate (L3T1).3.2.8 Sstorativity (or storage coefficient) (dimensionless).3.2.9 Ssspecific storage (L1).3.2.10 Ttransmissivity (L2T1).3.

20、2.11 bformation thickness (L).3.2.12 efracture aperture (L).3.2.13 gacceleration due to gravity (LT2).3.2.14 kpermeability (L2).3.2.15 nporosity (dimensionless).3.2.16 rwradius of test hole (L).3.2.17 ttime elapsed from start of test (T).3.2.18 dimensionless parameter.3.2.19 viscosity of water (ML1T

21、1).3.2.20 density of water (ML3).4. Summary of Test Method4.1 Aborehole is first drilled into the rock mass, intersectinggeological formations for which the transmissivity and stor-ativity are desired. The borehole is usually cored throughpotential zones of interest, and is later subjected to geophy

22、sicalborehole logging over these intervals. During the test, eachinterval of interest is packed off at top and bottom withinflatable rubber packers attached to high-pressure steel tubing.4.2 The test itself involves rapidly applying a constantpressure to the water in the packed-off interval and tubi

23、ngstring, and recording the resulting changes in water flow rate.The water flow rate is measured by one of a series of flowmeters of different sensitivities located at the surface. Theinitial transient water flow rate is dependent on the transmis-sivity and storativity of the rock surrounding the te

24、st intervaland on the volume of water contained in the packed-off intervaland tubing string.5. Significance and Use5.1 Test MethodThe constant pressure injection testmethod is used to determine the transmissivity and storativityof low-permeability formations surrounding packed-off inter-vals. Advant

25、ages of the method are: (1) it avoids the effect ofwell-bore storage, (2) it may be employed over a wide range ofrock mass permeabilities, and (3) it is considerably shorter induration than the conventional pump and slug tests used inmore permeable rocks.5.2 AnalysisThe transient water flow rate dat

26、a obtainedusing the suggested test method are evaluated by the curve-matching technique described by Jacob and Lohman (1)4andextended to analysis of single fractures by Doe et al. (2). If thewater flow rate attains steady state, it may be used to calculatethe transmissivity of the test interval (3).

27、NOTE 2The quality of the result produced by this standard isdependent on the competence of the personnel performing it, and thesuitability of the equipment and facilities used. Agencies that meet thecriteria of Practice D3740 are generally considered capable of competentand objective testing/samplin

28、g/inspection/etc. Users of this standard arecautioned that compliance with Practice D3740 does not in itself assurereliable results. Reliable results depend on many factors; Practice D3740provides a means of evaluating some of those factors.NOTE 3The function of wells in any unconfined setting in a

29、fracturedterrain might make the determination of k problematic because the wellsmight only intersect tributary or subsidiary channels or conduits. Theproblems determining the k of a channel or conduit notwithstanding, thepartial penetration of tributary channels may make determination of ameaningful

30、 number difficult. If plots of k in carbonates and other fracturedsettings are made and compared, they may show no indication that thereare conduits or channels present, except when with the lowest probabilityone maybe intersected by a borehole and can be verified, such problemsare described by Wort

31、hington (4) and Smart, 1999 (5). Additionalguidance can be found in Guide D5717.6. ApparatusNOTE 4A schematic of the test equipment is shown in Fig. 1.4The boldface numbers in parentheses refer to the list of references at the end ofthis standard.FIG. 1 Equipment SchematicD4630 1926.1 Source of Cons

32、tant PressureA pump or pressureintensifier capable of providing an additional amount of waterto the water-filled tubing string and packed-off test interval toproduce a constant pressure of up to 1 MPa in magnitude,preferably with a rise time of less than 1 % of one half of theflow rate decay (Q/Qo=

33、0.5).6.2 PackersHydraulically actuated packers are recom-mended because they produce a positive seal on the boreholewall and because of the low compressibility of water they arealso comparatively rigid. Each packer shall seal a portion of theborehole wall at least 0.5 m in length, with an applied pr

34、essureat least equal to the excess constant pressure to be applied tothe packed-off interval and less than the formation fracturepressure at that depth.6.3 Pressure TransducersThe pressure shall be measuredas a function of time, with the transducer located in thepacked-off test interval. The pressur

35、e transducer shall have anaccuracy of at least 63 kPa, including errors introduced by therecording system, and a resolution of at least 1 kPa.6.4 Flow MetersSuitable flow meters shall be providedfor measuring water flow rates in the range from 103cm3/s to103cm3/s. Commercially available flow meters

36、are capable ofmeasuring flow rates as low as 102cm3/s with an accuracy of61 % and with a resolution of 105cm3/s; these can testpermeabilities to 103md based on a 10-m packer spacing.Positive displacement flow meters of either the tank type(Haimson and Doe (6) or bubble-type (Wilson, et al (3) arecap

37、able of measuring flow rates as low as 103cm3/s; these cantest permeabilities to 104md based on a 10-m packer spacing.6.5 Hydraulic SystemsThe inflatable rubber packers shallbe attached to high-pressure steel tubing reaching to thesurface. The packers themselves shall be inflated with waterusing a s

38、eparate hydraulic system. The pump or pressureintensifier providing the constant pressure shall be attached tothe steel tubing at the surface.Aremotely controlled down-holevalve, located in the steel tubing immediately above the upperpacker, shall be used for shutting in the test interval and forins

39、tantaneous starting of tests.7. Procedure7.1 Drilling Test Holes:7.1.1 Number and OrientationThe number of test holeswill be sufficient to supply the detail required by the scope ofthe project. The test holes will be directed to intersect majorfracture sets, preferably at right angles.7.1.2 Test Hol

40、e QualityThe drilling procedure will pro-vide a borehole sufficiently smooth for packer seating, shallcontain no rapid changes in direction, and will minimizeformation damage.7.1.3 Test Holes CoredCore the test holes through zonesof potential interest to provide information for locating testinterval

41、s.7.1.4 Core DescriptionDescribe the rock core from thetest holes with particular emphasis on the lithology and naturaldiscontinuities.7.1.5 Geophysical Borehole LoggingLog geophysicallythe zones of potential interest. In particular, run electrical-induction and gamma-gamma density logs.Whenever pos

42、sible,also use sonic logs and the acoustic televiewer. Run other logsas needed.7.1.6 Washing Test HolesThe test holes must not containany material that could be washed into the permeable zonesduring testing, thereby changing the transmissivity and stor-ativity. Flush the test holes with clean water

43、until the return isfree from cuttings and other dispersed solids.7.2 Test Intervals:7.2.1 Selection of Test IntervalsDetermine test intervalsfrom the core descriptions, geophysical borehole logs, and, ifnecessary, from visual observation of the borehole with aborescope or TV camera.7.2.2 Changes in

44、LithologyTest each major change inlithology that can be isolated between packers.7.2.3 Sampling DiscontinuitiesDiscontinuities are oftenthe major permeable features in hard rock. Test jointed zones,fault zones, bedding planes, and the like, both by isolatingindividual features and by evaluating the

45、combined effects ofseveral features.7.2.4 Redundancy of TestsTo evaluate variability in trans-missivity and storativity, conduct three or more tests in eachrock type. If the rock is not homogeneous, the sets of testsshould encompass similar types of discontinuities.7.3 Test Water:7.3.1 Water Quality

46、Water used for pressure pulse testsshall be potable and free of particulates, and compatible withthe formation. Even small amounts of dispersed solids in theinjection water could plug the rock face of the test interval andresult in a measured transmissivity value that is erroneouslylow.7.3.2 Tempera

47、tureThe lower limit of the test water tem-perature shall be 5C below that of the rock mass to be tested.Cold water injected into a warm rock mass causes air to comeout of solution, and the resulting bubbles will radically modifythe pressure transient characteristics.7.4 Testing:7.4.1 Filling and Pur

48、ging SystemOnce the packers havebeen set, slowly fill the tubing string and packed-off intervalwith water to make sure that no air bubbles will be trapped inthe test interval and tubing. Close the downhole valve to shutin the test interval, and allow the test section pressures (asdetermined from dow

49、nhole pressure transducer reading) todissipate.7.4.2 Constant Pressure TestPressurize the tubing, typi-cally to between 300 and 600 kPa above the shut-in pressure.This range of pressures is in most cases sufficiently low tominimize distortion of fractures adjacent at the test hole, but inno case should the pressure exceed the minimum principalground stress. It is necessary to provide sufficient volume ofpressurized water to maintain constant pressure during testing.Open the downhole valve, maintain the co