1、Designation: E2928/E2928M 13E2928/E2928M 17Standard Practice forExamination of Drillstring Threads Using the AlternatingCurrent Field Measurement Technique1This standard is issued under the fixed designation E2928/E2928M; the number immediately following the designation indicates the yearof original
2、 adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval.A superscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This practice describes procedures to be followed during alternatin
3、g current field measurement examination of drillstringthreads on tubulars used for oil and gas exploration and production for detection and, if required, sizing of service-induced surfacebreaking discontinuities transverse to the pipe.1.2 This practice is intended for use on threads in any metallic
4、material.1.3 This practice does not establish acceptance criteria. Typical industry practice is to reject these connections on detection ofa confirmed crack.1.4 While the alternating current field measurement technique is capable of detecting discontinuities in these connections,supplemental surface
5、 NDT methods such as magnetic particle testing for ferrous metals and penetrant testing for non-ferrousmetals may detect more discontinuities.1.5 UnitsThe values stated in either inch-pound units or SI units are to be regarded separately as standard. The values statedin each system might not be exac
6、t equivalents; therefore, each system shall be used independently of the other. Combining valuesfrom the two systems may result in nonconformance with the standard.1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof th
7、e user of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use.1.7 This international standard was developed in accordance with internationally recognized principles on standardizationestablished in the Decision on P
8、rinciples for the Development of International Standards, Guides and Recommendations issuedby the World Trade Organization Technical Barriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2E543 Specification for Agencies Performing Nondestructive TestingE1316 Terminology for Non
9、destructive ExaminationsE2216E2261 Guide for Evaluating Disposal Options for Concrete from Nuclear Facility DecommissioningPractice forExamination of Welds Using the Alternating Current Field Measurement Technique2.2 ASNT Standards3SNT-TC-1A Personnel Qualification and Certification in Nondestructiv
10、e TestingANSI/ASNT-CP-189 Standard for Qualification and Certification of Nondestructive Testing Personnel2.3 ISO Standard:4ISO 9712 Non-Destructive Testing: Qualification and Certification of NDT Personnel1 This practice is under the jurisdiction of ASTM Committee E07 on Nondestructive Testing and
11、is the direct responsibility of Subcommittee E07.07 on ElectromagneticMethod.Current edition approved June 1, 2013June 1, 2017. Published June 2013June 2017. Originally approved in 2013. Last previous edition approved in 2013 asD2928/D2928M13. DOI: 10.1520/E2928_E2928M13.10.1520/E2928_E2928M17.2 For
12、 referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.3 Available from American Society for Nondestructive Testing (ASNT
13、), P.O. Box 28518, 1711 Arlingate Ln., Columbus, OH 43228-0518, http:/www.asnt.org.4 Available from International Organization for Standardization (ISO), ISO Central Secretariat, BIBC II, Chemin de Blandonnet 8, CP 401, 1214 Vernier, Geneva,Switzerland, http:/www.iso.org.This document is not an ASTM
14、 standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all
15、 cases only the current versionof the standard as published by ASTM is to be considered the official document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States13. Terminology3.1 For definitions of terms relating to this practice refer t
16、o Terminology E1316, Section A, Common NDT terms, and SectionC, Electromagnetic testing. The following definitions are specific to the alternating current field measurement technique:3.2 Definitions:3.2.1 detectorone or more coils or elements used to sense or measure a magnetic field; also known as
17、a receiver.3.2.2 excitera device that generates a time varying electromagnetic field, usually a coil energized with alternating current(AC); also known as a transmitter.3.2.3 uniform fieldas applied to nondestructive testing with magnetic fields, the area of uniform magnetic field over the surfaceof
18、 the material under examination produced by a parallel induced alternating current, which has been passed through the testpieceand is observable beyond the direct coupling of the exciting coil.3.3 Definitions of Terms Specific to This Standard:3.3.1 alternating current field measurement systemthe el
19、ectronic instrumentation, software, probes, and all associatedcomponents and cables required for performing an examination using the alternating current field measurement technique.3.3.2 boxthe female thread in a drillstring connection.3.3.3 Bxthe x component of the magnetic field, parallel to the t
20、hread root, the magnitude of which is proportional to thecurrent density set up by the electric field.3.3.4 Bzthe z component of the magnetic field normal to the examined pipe surface, the magnitude of which is proportionalto the lateral deflection of the induced currents in the plane of that surfac
21、e.3.3.5 configuration datastandardization data and instrumentation settings for a particular probe stored in a computer file.3.3.6 data sample ratethe rate at which data is digitized for display and recording, in data points per second.3.3.7 longitudinalfollowing from the above definition, a longitu
22、dinal discontinuity is parallel to the pipe axis and thereforeperpendicular to the scan direction.3.3.8 operational standardization blocka reference standard with specified artificial notches, used to confirm the operation ofthe system.3.3.9 pinthe male thread in a drillstring connection.3.3.10 sate
23、llite signalsBx and Bz signals observed when the probe passes a discontinuity in an adjacent thread root.3.3.11 surface plotfor use with array probes. This type of plot has one component of the magnetic field plotted over an area,typically as a color contour plot or 3-D wire frame plot.3.3.12 time b
24、ase plotsthese plot the relationship between Bx or Bz values with time.3.3.13 transverseas is normal in drilling, the terms transverse and longitudinal are defined in reference to the pipe axis.Therefore, a transverse discontinuity is parallel to the thread and hence to the scan direction. This is d
25、ifferent to the situation forweld inspection, covered in Guide E2216E2261.3.3.14 X-Y Plotan X-Y graph with two orthogonal components of magnetic field plotted against each other.NOTE 1Different equipment manufacturers may use slightly different terminology. Reference should be made to the equipment
26、manufacturersdocumentation for clarification.4. Summary of Practices4.1 In a basic alternating current field measurement system, a small probe is moved around the thread root. The probe containsan exciter coil, which induces anAC magnetic field in the material surface aligned to the direction of the
27、 thread root. This, in turn,causes alternating current to flow across the threads. The depth of penetration of this current varies with material type andfrequency but is typically 0.004 in. 0.1 mm deep in magnetic materials and 0.08 to 0.3 in. 2 to 7 mm deep in non-ferrousmaterials. Any surface brea
28、king discontinuities within a short distance of either side of the scan line at this location will interruptor disturb the flow of the alternating current. Measurement of the absolute quantities of the two major components of the surfacemagnetic fields (Bx and Bz) determines the severity of the dist
29、urbance (see Fig. 1) and thus the severity of the discontinuity.Discontinuity sizes, such as crack length and depth, can be estimated from the values of these quantities or the physical locationsof key points, or both, selected from the Bx and Bz traces along with the standardization data and instru
30、ment settings from eachindividual probe. This discontinuity sizing can be performed automatically using system software. Discontinuities essentiallyperpendicular to the thread may be detected (in ferritic metals only) by the flux leakage effect.4.2 Configuration data is loaded at the start of the ex
31、amination. System sensitivity and operation is verified using an operationstandardization block. System operation is checked and recorded prior to and at regular intervals during the examination. This canbe accomplished using discontinuity-sizing tables in the system software. Data is recorded in a
32、manner that allows archiving andsubsequent recall for each thread. Evaluation of examination results may be conducted at the time of examination or at a later date.The examiner generates an examination report detailing complete results of the examination.E2928/E2928M 1725. Significance and Use5.1 Th
33、e purpose of the alternating current field measurement method is to evaluate threads for surface breaking discontinuitiessuch as fatigue cracks running along the thread root. The examination results may then be used to determine the fate of the tool.This may involve re-examination by an alternative
34、technique, immediate scrapping of the tool, or reworking to removediscontinuities (beyond the scope of this practice). This practice is not intended for the examination of threads for non-surfacebreaking discontinuities.6. Basis of Application6.1 Personnel Qualificationif specified in the contractua
35、l agreement, personnel performing examinations to this practice shallbe qualified in accordance with a nationally or internationally recognized NDT personnel qualification practice or standard suchas ANSI/ASNT-CP-189 or SNT-TC-1A or ANSI/ASNT-CP-189, SNT-TC-1A, ISO 9712, or a similar document and ce
36、rtified bythe employer or certifying agent, as applicable. The practice or standard used and its applicable revision shall be identified in thecontractual agreement between the using parties6.2 Qualification of Nondestructive Evaluation Agenciesif specified in the contractual agreement, NDT agencies
37、 shall bequalified and evaluated as described in Specification E543, with reference to sections on electromagnetic examination. Theapplicable edition of Specification E543 shall be specified in the contractual agreement.7. Job Scope and Requirements7.1 The following items may require agreement by th
38、e examining party and their client and should be specified in the purchasedocument or elsewhere:7.1.1 Location and type of threaded component to be examined, design specifications, degradation history, previousnondestructive examination results, maintenance history, process conditions, and specific
39、types of discontinuities that are requiredto be detected, if known.7.1.2 The maximum recommended probe scan speed is to be stated by the manufacturer. However, detection of smallerdiscontinuities requires a slower probe scan speed or cleaning of surface, or both.7.1.3 Size, material grade and type,
40、and configuration of threads to be examined.7.1.4 A thread numbering or identification system.7.1.5 Extent of examination, for example: complete or partial coverage, which threads and to what extent.7.1.6 Type of alternating current field measurement instrument and probe; and description of operatio
41、ns standardization blockused, including such details as dimensions and material.7.1.7 Required thread cleanliness.7.1.8 Environmental conditions, equipment and preparations that are the responsibility of the client; common sources of noisethat may interfere with the examination, such as motor drive
42、for rotary table.7.1.9 Complementary methods or techniques may be used to obtain additional information.7.1.10 Acceptance criteria to be used in evaluating discontinuities.FIG. 1 Example Bx and Bz Traces as a Probe Passes Over a Crack (The orientation of the traces may differ depending upon the inst
43、ru-mentation.)E2928/E2928M 1737.1.11 Disposition of examination records and reference standards.7.1.12 Format and outline contents of the examination report.8. Interferences8.1 This section describes items and conditions, which may compromise the alternating current field measurement technique.8.2 M
44、aterial Properties:8.2.1 Although there are unlikely to be permeability differences in a ferromagnetic material between different parts of a thread,if a probe is scanned across a permeability change such as an area of residual magnetism, this may produce indications which couldbe similar to those fr
45、om a discontinuity. Differentiation between a discontinuity signal and a permeability change signal can beachieved by comparing scans from neighboring threads. The signal from a discontinuity will die away quickly. If there is nosignificant change in indication amplitude two or more threads away alo
46、ng the pipe axis then the indication is likely due to thepermeability changes in the component.8.3 Magnetic State:8.3.1 DemagnetizationIt must be ensured that the surface being examined is in a low magnetization state, or that anymagnetization is uniform over the surface. Therefore the procedure fol
47、lowed with any previous magnetic technique deployed mustinclude demagnetization of the surface, or ensuring that connections are magnetically saturated. This is because areas of remnantmagnetization, particularly where the leg of a magnetic particle examination yoke was sited, can produce loops in t
48、he X-Y plot,which may sometimes be confused with a discontinuity indication.8.4 Thread Geometry:8.4.1 When a probe scans away from the shoulder of a pin connection, the Bx indication value will decrease with little changein the Bz value. In the representative plot of Fig. 2, this appears as a drop i
49、n the X-Yplot.The Bx indication value will also decreaseas a probe approaches the open end of a thread (pin or box).8.5 Crack Geometry Effects:8.5.1 Since the effect of a discontinuity on the signals can be detected some distance away, “satellite” signals are observed asthe probe passes one thread (or two threads) away from a sufficiently-large discontinuity. The satellite signals will be smaller thanthe main discontinuity signal, and symmetrically spaced one thread revolution either side. Care should be taken not to classify thesesignals as additio
