1、Designation: D6167 11Standard Guide forConducting Borehole Geophysical Logging: MechanicalCaliper1This standard is issued under the fixed designation D6167; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision.
2、 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 guide covers the general procedures necessary toconduct caliper logging of boreholes, wells, access tubes,caissons, or shafts
3、(hereafter referred as boreholes) as com-monly applied to geologic, engineering, ground-water, andenvironmental (hereafter referred as geotechnical) investiga-tions. Caliper logging for mineral or petroleum exploration anddevelopment are excluded.1.1.1 This guide offers an organized collection of in
4、forma-tion or a series of options and does not recommend a specificcourse of action. This document cannot replace education orexperience and should be used in conjunction with professionaljudgment. Not all aspects of this guide may be applicable in allcircumstances. This ASTM standard is not intende
5、d to repre-sent or replace the standard of care by which the adequacy ofa given professional service must be judged, nor should thisdocument be applied without consideration of a projects manyunique aspects. The word “Standard” in the title of thisdocument means only that the document has been appro
6、vedthrough the ASTM consensus process.1.2 This guide defines a caliper log as a record of boreholediameter with depth.1.2.1 Caliper logs are essential in the interpretation ofgeophysical logs since they can be significantly affected byborehole diameter.1.2.2 Caliper logs are commonly used to measure
7、 boreholediameter, shape, roughness, and stability; calculate boreholevolume; provide information on borehole construction; anddelineate lithologic contacts, fractures, and solution cavitiesand other openings.1.2.2.1 Borehole-diameter information is essential for cal-culation of volumetric rate from
8、 flowmeter logs.1.2.2.2 Caliper logs provide useful information for boreholecompletion and testing.1.2.2.3 Caliper logs are used to locate the optimum place-ment of inflatable packers for borehole testing. Inflatablepackers can only form an effective seal within a specified rangeof borehole diameter
9、s, and can be damaged if they are set inrough or irregular parts of the borehole.1.2.2.4 Caliper logs are used to estimate the volume ofborehole completion material (cement, gravel, etc.) needed tofill the annular space between borehole and casing(s) or wellscreen.1.2.2.5 Caliper logs may be applied
10、 to correlate lithologybetween boreholes based upon enlargements related to lithol-ogy. The measured borehole diameter may be significantlydifferent than the drilled diameter because of plastic formationsextruded into the borehole and friable formations enlarging theborehole. A series of caliper log
11、s may also show increases ordecreases in borehole diameter with time.1.3 This guide is restricted to mechanically based deviceswith spring-loaded arms, which are the most common calipersused in caliper logging with geotechnical applications.1.4 This guide provides an overview of caliper logging,incl
12、uding general procedures, specific documentation, calibra-tion and standardization, and log quality and interpretation.1.5 To obtain additional information on caliper logs seeSection 9 of this guide.1.6 This guide is to be used in conjunction with GuideD5753.1.7 This guide should not be used as a so
13、le criterion forcaliper logging and does not replace professional judgment.Caliper logging procedures should be adapted to meet theneeds of a range of applications and stated in general terms sothat flexibility or innovation is not suppressed.1.8 The geotechnical industry uses English or SI units. T
14、hecaliper log is typically recorded in units of inches, millimetres,or centimetres.1.9 This guide does not purport to address all of the safetyand liability problems (for example, lost or lodged probes andequipment decontamination) associated with its use.1This guide is under the jurisdiction ofASTM
15、 Committee D18 on Soil and Rockand is the direct responsibility of Subcommittee D18.01 on Surface and SubsurfaceCharacterization.Current edition approved May 1, 2011. Published June 2011. Originallyapproved in 1997. Last previous edition approved in 1997 as D6167-97(2004). DOI:10.1520/D6167-11.1*A S
16、ummary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.1.10 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsi
17、bility 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 ContainedFluidsD5088 Practice for Decontamination
18、of Field EquipmentUsed at Waste SitesD5608 Practices for Decontamination of Field EquipmentUsed at Low Level Radioactive Waste SitesD5753 Guide for Planning and Conducting Borehole Geo-physical Logging3. Terminology3.1 Definitions: Definitions shall be in accordance withTerminology D653, Section 12,
19、 Ref (1),3or as defined below:3.1.1 accuracy, nhow close a measured log values ap-proaches true value. It is determined in a controlled environ-ment. A controlled environment represents a homogeneoussample volume with known properties.3.1.2 depth of investigation, nthe radial distance from themeasur
20、ement point to a point where the predominant measuredresponse may be considered centered, that is not to be confusedwith borehole depth (for example, distance) measured from thesurface.3.1.3 measurement resolution, nthe minimum change inmeasured value that can be detected.3.1.4 repeatability, nthe d
21、ifference in magnitude of twomeasurements with the same equipment and in the sameenvironment.3.1.5 vertical resolution, nthe minimum thickness thatcan be separated into distinct units.3.1.6 volume of investigation, nthe volume that contrib-utes 90 % of the measured response. It is determined by acom
22、bination of theoretical and empirical modeling. The vol-ume of investigation is non-spherical and has gradationalboundaries.4. Summary of Guide4.1 This guide applies to borehole caliper logging and is tobe used in conjunction with Guide D5753.4.2 This guide briefly describes the significance and use
23、,apparatus, calibration and standardization, procedures, andreports for conducting borehole caliper logging.5. Significance and Use5.1 An appropriately developed, documented, and executedguide is essential for the proper collection and application ofcaliper logs. This guide is to be used in conjunct
24、ion with GuideD5753.5.2 The benefits of its use include the following: improvingselection of caliper logging methods and equipment, caliperlog quality and reliability, and usefulness of the caliper log datafor subsequent display and interpretation.5.3 This guide applies to commonly used caliper logg
25、ingmethods for geotechnical applications.5.4 It is essential that personnel (see the Personnel sectionof Guide D5753) consult up-to-date textbooks and reports onthe caliper technique, application, and interpretation methods.6. Interferences6.1 Most extraneous effects on caliper logs are caused byins
26、trument problems and borehole conditions.6.2 Instrument problems include the following: electricalleakage of cable and grounding problems, temperature drift,wear of mechanical components including the hinge pins andin the linear potentiometer (mechanical hysteresis), damagedor bent arms, and lack of
27、 lubrication of the mechanicalcomponents.6.3 Borehole conditions include heavy drilling mud, bore-hole deviation, and drilling-related borehole irregularities.7. Apparatus7.1 A geophysical logging system has been described in thegeneral guide (see the Apparatus section of Guide D5753).7.2 Caliper lo
28、gs may be obtained with probes having asingle arm, three arms (averaging or summation), multipleindependent arms (x-y caliper), multiple-feeler arms, bowsprings, or gap wheels. Single-arm and three-arm averagingprobes are most commonly used for geotechnical investiga-tions.7.2.1 A single-arm caliper
29、 commonly provides a record ofborehole diameter while being used to decentralize anothertype of log, such as a side-collimated gamma-gamma probe(see Fig. 1). The caliper arm generally follows the high side of2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Custome
30、r Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3The boldface numbers given in parentheses refer to a list of references at theend of the text.FIG. 1 Probe for Making Side-Collimated Gamma-Gamma Logswi
31、th Single-Arm Caliper (2)D6167 112a deviated hole. The single-arm decentralizing caliper may nothave the resolution needed for some applications.7.2.2 The three-arm averaging or summation caliper hasarms of equal length oriented 120 apart (see Fig. 2). All armsmove together, which provides an averag
32、e diameter measure-ment. This caliper provides higher resolution than the single-arm caliper measurement (see Fig. 3).7.2.3 Multiple independent arm calipers generally havethree or four independent arms of equal length; these arms aresometimes oriented. Horizontal resolution, that provides accu-rate
33、 borehole-diameter measurement regardless of boreholeshape, is related to the number of independent arms. In general,calipers with four or more independent arms will have higherresolution than three-arm averaging (see Fig. 3). The fourindependent-arm caliper log may show borehole elongation(elliptic
34、al borehole shape) and better indicates the actualirregularity of the borehole.7.3 Caliper probes using arms are typically spring loaded.The arms are retracted and opened with an electric motor andretention spring. The arms and gears are lubricated. Caliperprobes closed by hand are held closed with
35、an electric solenoidor weighted retention ring that is released with a sudden drop.Typically, the caliper arms are mechanically connected to alinear or rotary potentiometer such that changes in the angle ofthe arms causes changes in resistance. These changes inresistance are proportional to average
36、borehole diameter. Insome probes, the voltage changes are converted to a varyingpulse rate or digitized downhole to eliminate or minimize cabletransmission noise. Different arm length can be used tooptimize sensitivity for the borehole-diameter range expected.7.4 The concepts of volume of investigat
37、ion and depth ofinvestigation are not applicable to caliper logs since it is asurface-contact measurement.7.5 Vertical resolution of caliper measurements is a functionof the size of the contact surface (arm tip or pad), the responseof the mechanical and electronic components, and digitizinginterval
38、used. The theoretical limit of vertical resolution isequal to the width of the caliper pad or tip. Selection of armlengths and angle, and tip diameter will affect sensitivity.Shorter arms generally will provide more detail of the rugosity(borehole roughness as defined by Ref. (2) of the boreholewall
39、 than longer arms. However, size of caliper probe andborehole diameter may also determine arm lengths used.7.6 Measurement resolution of typical caliper probes is 0.05in. (0.13 cm) of borehole diameter.7.7 A variety of caliper logging equipment is available forgeotechnical investigations. It is not
40、practical to list all of thesources of potentially acceptable equipment.8. Calibration and Standardization of Caliper Logs8.1 General:8.1.1 National Institute of Standards and Technology(NIST) calibration and standardization procedures do not existfor caliper logging.8.1.2 Caliper logs can be used i
41、n a qualitative (for example,comparative) or quantitative (for example, borehole diametercorrections) manner depending upon the project objectives.8.1.3 Caliper calibration methods and frequency shall besufficient to meet project objectives.8.1.3.1 Calibration and standardization should be performed
42、each time a caliper probe is suspected to be damaged, modified,repaired, and at periodic intervals.8.2 Calibration is the process of establishing values forcaliper response and is accomplished with a physical model ofa known diameter. Calibration data values related to thephysical properties (for ex
43、ample, borehole diameter, rough-ness) may be recorded in units (for example, counts persecond), that can be converted to units of length (for example,inches, millimetres, or centimetres.)FIG. 2 Three-Arm Averaging CaliperFIG. 3 Caliper Logs From Probes Having Four Independent Arms,Three Averaging Ar
44、ms, and a Single Arm, Madison LimestoneTest Well 1, Wyoming (2)D6167 1138.2.1 At least two, and preferably more, values, whichapproximate the anticipated operating range, are needed toestablish a calibration curve (for example, 4- and 10-in. (10.2-and 25.4-cm) rings) if the borehole diameter to be l
45、ogged is 5in. (12.7 cm).8.2.2 Physical models of measured diameter that may beused to calibrate the caliper response may include rings or barsmade of rigid materials that are not easily deformed and resistwear.8.2.2.1 Calibration of caliper probes is done most accuratelyin rings of different diamete
46、rs.8.2.2.2 A calibration bar is a plate that is drilled and markedat regular intervals and machined to fit over the body of theprobe (see Fig. 4). One arm is placed in the appropriate hole forthe range to be logged.8.2.2.3 Calibration can be checked by using casing ofmeasured diameter logged in the
47、borehole.8.3 Standardization is the process of checking loggingresponse to show evidence of repeatability and consistency.8.3.1 Calibration serves as a check of standardization.8.3.2 A representative borehole may be used to periodicallycheck caliper response providing the borehole environmentdoes no
48、t change with time. Caliper response may not repeatexactly because the probe may rotate, causing the arms tofollow slightly different paths within the borehole.9. Procedure9.1 See the Procedure section of Guide D5753 for planninga logging program, data formats, personnel qualifications, fielddocumen
49、tation, and header documentation.9.2 Caliper specific information (for example, arm length)should be documented.9.3 Identify caliper logging objectives.9.4 Select appropriate equipment to meet objectives.9.4.1 Caliper equipment decontamination is addressed ac-cording to project specifications (see Practice D5088 fornon-radioactive waste sites and Practice D5608 for low levelradioactive waste sites). Some materials commonly used forcaliper-arm lubrication may be environmentally sensitive.9.5 Select the order in the logging sequence in which thecaliper probe is to be run (se
