The requirements for each applicable qualification shall include the following as a minimum: a training and experience commensurate with the inspector’s level of qualification; b written
Symbols
D FR diameter of float bore recess
D LTorq diameter of low-torque counterbore
D RG diameter of stress-relief groove
D tj outside diameter of tool joint d tj inside diameter of tool joint l e elevator groove depth l s slip groove depth
L BC length of box connection
L br length of baffle recess
L BT length from shoulder to non-pressure flank on last full-depth thread box
L c minimum-length full-crested threads
L Cyl length from last scratch to beginning of the tapered section of boreback
L eg length of elevator groove
L fn length of fish neck
L PC length of pin thread
L pb length of pin base
L RG length of stress-relief groove
L sg length of slip groove
L Tpr length of tapered section of boreback
L X length from shoulder to last thread scratch in boreback cylinder
Q c counterbore diameter r EG elevator groove radius r SG slip groove radius
S w shoulder width t average wall thickness
Abbreviated terms
AC alternating current dB decibels
FLUT full-length ultrasonic transverse
FWAC full-wave rectified alternating current
HWAC half-wave alternating current
HWDP heavy-weight drill pipe
SOBM synthetic oil-based mud
SWBM synthetic water-based mud
WBM water-based mud àW microwatts
Basis for inspection
ISO 10407 outlines practices for inspecting, evaluating, and classifying used drill stem elements, with Annex E offering guidelines to help users determine the necessary level of inspection.
The inspection levels outlined in Annex B categorize practices into four distinct types First, standard inspections deemed mandatory for classification represent the minimum requirements for drill stem element classification Second, when moderate service inspections are required, the mandatory inspections specified serve as the minimum classification criteria for the drill stem element Third, for critical service inspections, the mandatory inspections outlined establish the minimum classification requirements for the drill stem element Lastly, inspections that are not classified as mandatory may still be determined based on specific drilling conditions.
5.1.2 Required inspection tables in Annex B
The tables in Annex B list the required inspections for each of the above levels inspection The following is a list of drill stem elements covered in the tables in Annex B
Table B.1 identifies the inspections available and specifies which inspections are required for each level of inspection for used drill pipe bodies, as well as the additional services available
Table B.2 identifies the inspections available and specifies which inspections are required for each level of inspection for used tool joints, as well as the additional services available
Table B.3 outlines the available inspections and indicates the required inspections for each inspection level concerning connections utilized in bottom-hole assemblies, along with the additional services offered.
Tables B.4 to B.14 outline the available inspections and detail the required inspections for each level of inspection concerning bottom-hole-assembly drill stem elements, excluding connection inspections, along with the additional services offered.
Table B.15 identifies the inspections available and specifies which inspections are required for each level of inspection for used tubing work strings.
Repeatability of results
Non-destructive inspection and measurement processes inherently produce some variability of results
Variability in non-destructive inspection systems can be attributed to several factors, including the allowable choices in practice selection for inspecting specific attributes, the options available for reference standards, differences in mechanical and electronic designs among equipment manufacturers, and the inherent lack of exact repeatability in the performance of a single inspection system setup.
Ordering information
When ordering the inspection of used drill stem elements under ISO 10407, equipment owners must provide specific information for each size and type of element, including the inspections to be conducted, any applicable reference standards, acceptance criteria, and instructions for marking.
General
The agency responsible for field inspections must establish and uphold a comprehensive quality management program This program should be thoroughly documented and include written procedures for all inspections conducted, along with detailed procedures, control features, and necessary documentation.
The agency's quality programme shall address calibration of equipment The frequency, range, accuracy and procedure for calibration, control features and documentation shall be included
The agency's quality program will incorporate documentation that confirms the inspection system's ability to detect the necessary reference indicators This verification process will be conducted in alignment with sections 6.2 to 6.6.
Standardization and operating procedures
Standardization procedures differ based on equipment types, requiring written protocols that specify the minimum reference indicator response and acceptable signal-to-noise ratio limits These operating procedures must outline necessary steps, control settings, and parameter limits, including the use of specialized electronic circuits, detector arrays, and applicable velocity ranges Additionally, it is essential to implement procedures ensuring that all testing equipment and materials operate within the temperature and humidity parameters set by the manufacturer.
Equipment description
The equipment used to conduct the inspection should be described in sufficient detail to demonstrate that it meets the requirements.
Personnel qualification
The agency's quality programme shall include provisions for the education, training and qualification of personnel performing inspections in accordance with this part of ISO 10407
Documentation of qualification of inspection personnel shall meet the requirements of Clause 7.
Dynamic test data demonstrating the system capabilities for detecting the reference
There are various methods to verify system capability, including statistical assessment of inspection performance and the use of reference standards One approach involves establishing inspection-system parameters and measuring the response amplitudes of reference flaws to determine the distribution of these amplitudes, which forms the basis for evaluating the inspection system's capability Alternatively, capability can be demonstrated for each inspection order by standardizing the system according to written procedures and inspecting a reference standard at multiple positions to ensure reliability across all quadrants.
Reports
Reports shall include all system settings, signal archival media, traceability of calibration, standardization and set- up procedures and a drawing of the test standard
General
Clause 7 sets forth the minimum requirements for qualification and certification (where applicable) of personnel performing field inspection of used drill stem elements.
Written procedure
Agencies performing inspection of used drill stem elements in accordance with this part of ISO 10407 shall have a written procedure for education, training, experience and qualification of personnel
The written procedure shall establish the following: a) administrative duties and responsibilities for execution of the written procedure; b) personnel qualification requirements; c) required documentation verifying all qualifications.
Qualification responsibility and requirements
The agency is responsible for establishing the qualification requirements for inspection personnel, which must include adequate training and experience relevant to the inspector's qualification level Additionally, inspectors must pass written and practical examinations with satisfactory grades, undergo a vision examination, and possess knowledge of ISO 10407 and related industry standards.
Training programmes
All qualified personnel shall have completed a documented training programme designed for that level of qualification Training may be given by the agency or an outside agent
The program will encompass the principles and procedures of each relevant inspection method, detailing the standardization and operation of inspection equipment, as well as the pertinent sections of applicable industry standards.
Examinations
Examinations may be given by the agency or by an outside agent
All inspection personnel must complete specific examinations, including written tests on inspection methods, procedures, and relevant standards such as ISO, API, or ASTM They are also required to pass a hands-on examination that covers apparatus assembly, inspection techniques, and report preparation Additionally, an annual vision examination is necessary to ensure the ability to read J-2 letters on a Jaeger number 2 test chart from a distance of 305 mm to 381 mm (12 in to 15 in), with alternative acceptable tests including the Titmus number 8 target or a Snellen fraction of 20/25 (0.8), conducted by a qualified medical practitioner.
Experience
All candidates for qualification shall have the experience required by the written procedure.
Re-qualification
Re-qualification requirements shall be defined in the written procedure
Re-qualification is required at least every five years for all personnel
Re-qualification of personnel is required if an individual has not performed defined functions within the previous twelve months or if an individual changes employers
To maintain re-qualification, all personnel must achieve a satisfactory score on a written exam covering current inspection procedures and industry standards, and must also demonstrate ongoing satisfactory technical performance.
Documentation
Record retention and documentation shall be required for all qualification programmes
To comply with minimum requirements, agencies must retain essential documents, including records of qualified personnel that demonstrate completion of training programs and relevant experience, examination results available for review upon request, and individual records for each qualified person, which must be kept for at least one year following the revocation of their qualification.
All qualifications and related documents shall be approved by authorized agency personnel.
NDT personnel certification
A programme for certification of NDT personnel shall be developed by the agency ISO 11484 may be used as a guideline
NOTE For the purposes of this recommendation, ASNT SNT-TC-1A is equivalent to ISO 11484
The administration of the NDT personnel-certification programme shall be the responsibility of the agency
General
Clause 8 covers the general procedures applicable to all inspection methods contained in this part of ISO 10407.
Owner/operator work site requirements for quality inspection
The owner/operator must ensure that items are delivered to a site for inspection, where they are placed on racks or tables at an appropriate height Tubular products, including pipes and collars, should be stored in a single layer with enough space to allow for a complete revolution during inspection Non-compliance with these requirements compromises the inspection quality as outlined in ISO 10407.
Thread protectors shall be provided.
Documents at job site
Agency-controlled inspection documents related to the job and relevant reference documents shall be available at the job site Additional documentation of inspector certifications shall be available.
Pre-inspection procedures
Each inspection shall start with the correct equipment available and in good working condition
Before setting up the equipment, the agency must verify that the drill stem elements designated for inspection match the owner's order This involves comparing the job order details with the markings on the drill stem elements, including labels, size, ID, weight code, grade, manufacturer, features, and connections.
All inspections must be traceable to individual items by assigning unique identification numbers or recording permanent serial numbers for each inspected length In the case of drill pipes, this identification number is die-stamped on the 35° (or 18° if applicable) shoulder of the pin-end tool joint.
Over time, drill strings often consist of replacement or additional lengths, necessitating the addition of the serial number from the latest inspection to the taper shoulder, alongside previous inspection numbers Each set of numbers must include a method for identifying the inspection classification and the most recent application (refer to Figure 3) This is usually achieved by adding punch marks to indicate classification, along with numbers representing the month and year of the inspection and the agency mark It is essential that inspection punch marks and classification bands are applied only after all required inspections have been completed.
Drill-string components, such as drill pipes, are assigned a permanent serial number by either the manufacturer or the owner With mutual consent between the owner and the inspection agency, this permanent identification system can replace the standard serial numbering method when it is accessible and clear Additionally, if any component lacks a visible or identifiable serial number, it will be assigned a new number as agreed upon with the owner.
To ensure clarity and longevity, new serial numbers must not overlap with existing ones They should be placed in low-stress areas of the component, where wear and damage to the numbers are minimized.
Each drill-string element must undergo all necessary procedures for its classification before inspection is completed If issues like cracks, holes, or irreparable conditions are found prior to finishing these procedures, the inspection may be halted The decision to terminate the inspection upon discovering a rejectable condition should be mutually agreed upon by the element owner and the inspection agency.
Drill-pipe and tool-joint classification markings
Permanent markings indicating the classification of the pipe must be stamped on the 35° or 18° sloping shoulder of the pin-end tool joint or in a low-stress section of the tool joint that can withstand operational conditions It is important to avoid cold steel stamping on the outer surface of the tube body.
One centre punch denotes ―premium‖, two denote ―class 2‖, three denote ―class 3‖ and four denote scrap
Paint-band markings indicating the condition of drill pipes and tool joints must be applied based on specific criteria: a) Markings are necessary only on the tube if the tool joint is of the same class or better b) If the tool joint is classified lower than the tube, markings must be applied to the tool joint c) Tool joints needing thread and seal repairs should be marked as illustrated in Figure 3.
Post-inspection procedures
Each length of pipe, tool joint, and bottom-hole assembly component shall be classified according to the requirements in Clause 10
Remove all magnetic particles, liquid-penetrant developer and cleaning material from the connections
Count the lengths in each of the classification categories Verify the totals after the initial count
After inspection, ensure the threads are clean and dry before applying a rotary shoulder thread compound that meets API RP 7A1 standards or the specifications of the owner/operator It is essential to coat the entire threaded area, including shoulders and thread roots, around the full circumference In extremely cold conditions, warming the thread compound may be necessary for proper application Avoid thinning thread compounds with solvents, and if available, reinstall clean thread protectors, tightening them securely with a wrench.
CAUTION — The material safety data sheets for thread compounds should be read and observed Store and dispose of containers and unused compound in accordance with appropriate regulations
Before departing from the job site, the agency must confirm that all tasks are completed, including securing each row of pipe to prevent any loose or unsecured pipes from rolling or falling, ensuring that no pipes are left on the ground Additionally, the site should be left clean and organized, free from any job-related debris, and all cleaning solvents must be disposed of properly.
When handling solvents, cleaning agents, and generated waste, it is crucial to recognize that these materials may contain hazardous substances Always consult material safety data sheets and adhere to safety precautions Proper storage, transport, usage, and disposal of waste materials and their containers must be carefully managed, in compliance with relevant regulations regarding the disposal of used solvents and waste.
In 8.6.6 the practice for the uniform inspection marking of used drill stem elements is set forth
The classification of each inspected length shall be performed only by a qualified inspector However, any crew member may be directed to apply the appropriate descriptions, stencils and paint bands
Each inspected drill pipe must feature a unique number stamped on the 35° sloping pin tool-joint shoulder, preceded by the month and year of inspection, the classification stamp, and the name or mark of the inspecting company Stamps should not exceed 10 mm (3/8 in) in size While the sequence number stamp is optional if serial numbers are used for traceability, all other required information must be included The classification stamp is to be applied only after all necessary inspections are completed and must indicate the lowest classification for both the tube and tool joints.
Each length of pipe will be marked with paint-band classifications according to the specifications outlined in Table B.18 for used drill pipe and Table B.19 for used work-string tubing The paint bands should be applied at approximately 0.5 meters.
(18 in) from the 35° sloping pin shoulder Paint bands shall be approximately 51 mm (2 in) wide
All downgraded pipes must feature a 25 mm (1 in) band around the defective area, which should be boxed in The band's color will indicate the downgrade classification of the defect, and the reason for rejection must be clearly marked next to the band using a paint marker or another indelible marker.
Any tool joint failing to meet the minimum specifications for outside diameter, inside diameter, or shoulder width as outlined in Table C.6 (Table D.6) will be marked with a paint band at its center This band signifies that the tool joint's torsional strength is below 80% of the necessary pipe-body torsional strength.
All tool-joint connections that are damaged and need shop repair must have a 25 mm (1 in) red band painted on the outside diameter near the sealing shoulder The reason for rejection should be clearly marked next to the red band using a durable paint marker or similar method to withstand repair processes These markings must be removed once the repair is completed.
Field-repairable connections that are not repaired during the inspection must be marked with a 25 mm (1 in) green band on the outer diameter, positioned next to the sealing shoulder Additionally, the reason for rejection should be clearly indicated on the part next to the green band using a permanent marker It is important to remove these markings once the repair has been completed.
A paint marking with supplementary information can be applied to the tube body next to the classification band(s) These optional markings may indicate the agency, work order number, inspection level, any additional inspections conducted, and the inspection date (month and year) The lettering must be a minimum size.
Paint stencil markings for landing strings shall include the minimum remaining wall used as the basis for acceptance
2 classification paint bands for drill pipe and tool joints
3 stencil/stamp for permanent marking for classification of drill-pipe body as follows:
Tool-joint and drill-pipe classification
Number and colour of bands
Tool-joint condition Colour of bands
Premium class Two white Scrap or shop repair Red
Class 2 One yellow Field repairable Green
Figure 3 — Drill-pipe and tool-joint colour code identification
8.6.6.4 Drill collars and other bottom-hole assembly drill stem elements
Markings should be painted near the pin shoulder to indicate the agency, work-order number, inspection level, any optional inspections conducted, and the date of the inspection (month and year).
Each acceptable BHA component shall receive a white classification paint band Paint bands shall be placed approximately 152 mm (6 in) from the pin shoulder
All cracked or damaged components must be marked with a red paint band encircling the defective area Additionally, the reason for rejection should be clearly noted next to the red paint band using a permanent marker.
All connections that are damaged and need shop repair must have a 25 mm (1 in) red band painted on the outer diameter near the sealing shoulder The reason for the rejection should be clearly marked next to the red band using a permanent marker After the repair is completed, these markings must be removed.
Field-repairable connections that are not repaired during inspection must be marked with a 25 mm (1 in) green band on the outer diameter near the sealing shoulder Additionally, the reason for rejection should be clearly indicated next to the green band using a permanent marker It is important to remove these markings once the repairs have been completed.
8.6.7 Documentation — On-site inspection summaries
On-site inspection summaries for BHA elements must detail the inspected part's description and serial number, specify the type of inspection conducted, present the inspection results, indicate the inspection date, and outline all conditions that led to the rejection of any part.
9 General non-destructive inspection method requirements
General
Clause 9 provides descriptions of, and capability requirements for, inspection tools required for inspection of used drill pipe and bottom-hole assembly equipment.
Equipment
These requirements shall be applicable to equipment used for visual and dimensional inspection of used drill stem elements
9.2.2 Precision callipers (micrometer, vernier or dial)
The instrument must be calibrated following the agency's quality program, with calibration checks documented on the caliper and in a log This log should include the calibration check date, the due date, and the initials of the individual who conducted the check.
9.2.3 Non-adjustable length- and diameter-measuring devices
Length- and diameter-measuring devices consist of steel rules, steel length or diameter measuring tapes and other non-adjustable measuring devices
Accuracy verification shall be defined in the agency's quality programme
The instrument must be calibrated following the agency's quality program, with calibration checks documented on the caliper and in a log This log should include the calibration check date, the due date, and the initials of the individual who conducted the check.
Illumination
Direct daylight conditions do not require a check for surface illumination
9.3.1.2 Night and enclosed-facility illumination
The diffused-light level at the surfaces being inspected shall be a minimum of 538 lx (50 ft-candles)
Illumination in fixed-location facilities must adhere to the agency's quality program, with checks documented in a log that includes the date, reading, and the initials of the individual conducting the check This record should be readily accessible on-site.
9.3.1.3 Night illumination with portable equipment
The diffused-light level at the surfaces being inspected shall be a minimum of 538 lx (50 ft-candles)
Ensure proper lighting is confirmed at the start of the job to effectively illuminate the surfaces being inspected Additionally, check the illumination throughout the job whenever there are changes in the position or intensity of the lighting fixtures.
Light meters for verifying illumination must be calibrated according to the agency's quality program Calibration checks should be documented on the meter and in a log, including the calibration date, due date, and the initials of the individual who conducted the check.
The reflecting surface shall be a non-tinted mirror that provides a non-distorted image The reflecting surface shall be flat and clean
A portable light producing an intensity greater than 1 076 lx (100 ft-candles) at the maximum inspection distance may be used for illumination of inside surfaces
A light source having documented, demonstrated capability may be used for illumination of inside surfaces The lens of the light source shall be kept clean
At the beginning of a job and whenever equipment is reassembled, the resolution of the borescope or other optical internal inspection devices must be verified This is done by ensuring that the date on a coin, no taller than 1.0 mm (0.040 in), or Jaeger J-4 letters positioned within 102 mm (4.0 in) of the objective lens, are clearly readable through the assembled device.
Magnetic-particle-inspection equipment
Magnetizing current power supplies must be equipped with an ammeter to measure the magnetizing current These ammeters should be calibrated according to the agency's quality program, with calibration details recorded on the instrument and in a log This log must include the calibration date, the due date for the next calibration, and the initials of the individual who performed the calibration.
A longitudinal magnetic field is induced by placing a coil around the product and applying a current The number of turns of the coil shall be clearly marked on the coil
Coils must be inspected to ensure the integrity of their internal wire turns, following the agency's quality program This verification is usually performed by comparing the current resistance or magnetic flux values to the baseline measurements taken when the coil was new.
The verification check shall be recorded in a log with the date of the calibration check, the due date and the initials of the person who performed the check
Inserting an insulated conductor within the product generates a circumferential magnetic field, which is achieved by completing the circuit to the power supply and energizing it with the specified current outlined in Table C.2 (Table D.2).
An audible or visible annunciator can complement the ampere meter to signal insufficient current Additionally, it is essential to insulate the conductor from the product surface to avoid electrical contact or arcing.
Yokes are portable magnetizing tools designed to identify flaws on surfaces in any orientation They feature either fixed or adjustable legs and can operate using alternating or direct current For inspecting curved surfaces, adjustable legs are advantageous as they ensure consistent contact with the inspection area, accommodating various contours.
AC-energized yokes shall be capable of lifting 4,5 kg (10.0 lbs) at the maximum pole spacing that can be used for inspection
DC-energized yokes shall be capable of lifting 18 kg (40 lbs) at the maximum pole spacing that can be used for inspection
Yokes are typically evaluated for their lifting capacity using a steel bar, plate of suitable mass, or a calibrated magnetic-mass lift-test bar The frequency and procedures for conducting lift tests must align with the agency's quality program Calibration checks should be documented on the yoke and in a log, including the date of the check, the due date, and the initials of the individual who performed the calibration.
When using coils or yokes with active wet magnetic-particle inspection, the power circuit should include a ground- fault interrupter
Acceptable field indicators, such as slotted shims, strips, and pie field indicators, must effectively retain magnetic particles in a magnetic field of around 5 Gs These magnetic-particle field indicators are designed solely to detect the presence of an external magnetic field, specifically focusing on the flux lines in air rather than within the material itself.
Magnetometers and gauss meters measure the strength of external magnetic fields, providing consistent readings for comparison When the field strength indicator shows similar values at both ends of a pipe, it indicates that the magnetic fields within the pipes are approximately equal.
Gauss meters used for measuring relative magnetic field strength must be calibrated according to the agency's quality program Calibration checks should be documented on the meter and in a log, including the calibration date, due date, and the initials of the individual who conducted the check.
Magnetometers must undergo accuracy testing as part of the agency's quality program Calibration checks should be documented on the magnetometer itself and in a log, including the calibration date, the due date for the next check, and the initials of the individual who conducted the check.
Magnetic particles are used to indicate imperfections that cause magnetic-flux leakage Particles may be applied either dry or in suspension (wet)
Dry magnetic particles must be distinct from the product surface and are not to be reused The particle mixture should include various sizes, with at least 75% of the mass being finer than 150 µm and a minimum of 15% finer than 45 µm It is essential that the mixture is free from contaminants such as moisture, dirt, and sand Additionally, a manufacturer's batch or lot check may be conducted to ensure the particles possess high permeability and low retentivity.
Fluorescent magnetic particles are suspended in a low-viscosity solution (5 cSt or less) that is non-fluorescent, has a flash point above 93 °C (200 °F), and ensures complete surface wetting When exposed to ultraviolet light, these particles emit a glow To avoid washing away weakly held indications, wet fluorescent particles should be applied using low-velocity flow Proper application can be achieved through recirculating systems, spray containers, or other suitable methods.
The solution shall be mixed according to the manufacturer's instructions and agitated either continuously or periodically Concentration shall be between 0,1 % volume fraction and 0,4 % volume fraction Settling test time is
Oil-based carriers require a settling time of 1 hour, while water-based carriers need 30 minutes Settling tests should be conducted in a vibration-free and non-magnetic environment Alternatively, a manufacturer's lot test can be utilized instead of the settling test for particles contained in aerosol containers.
The concentration of the solution shall be checked prior to use The concentration of the solution in recirculating systems shall be verified at least once during each shift
9.4.8.4 Black magnetic particle and white background
The wet black-particle manufacturer must supply a white background coating that is compatible with the particles, ensuring that the total coating thickness does not exceed 0.05 mm (0.002 in) at the time of inspection The black particles are suspended in a low-viscosity solution (5 cSt or less) with a flash point above 93 °C (200 °F) to ensure complete surface wetting To avoid washing away weakly held indications, particles should be applied using low-velocity flow, utilizing recirculating systems, spray containers, or other appropriate methods for optimal application.
Ultraviolet light is used to illuminate fluorescent-dyed magnetic particles, requiring a properly filtered mercury arc lamp or similar source that emits wavelengths around 365 nm with a minimum intensity of 1,000 µW/cm² at the inspection surface The intensity must be measured using an ultraviolet light sensor directed towards the source Additionally, the ambient visible light intensity at the inspection surface should not exceed 21.5 lx (2 ft-candles) during the ultraviolet light inspection.
Ultrasonic
The gauge's readout linearity will be calibrated following the agency's quality program, with records maintained both on the instrument and in a log This documentation will include the calibration date, the due date for the next calibration, and the initials of the individual who performed the calibration.
When using an ultrasonic gauge to assess the remaining wall thickness above an internal surface imperfection, the ultrasonic-gauge-transducer combination must detect a flat-bottomed hole of 0.79 mm (0.031 in) located at least 9.7 mm (0.38 in) from the front surface of a parallel surface test block The accuracy of the remaining wall thickness measurement should be within 0.25 mm (0.010 in) This capability verification may be included in the agency's periodic calibration, and if conducted during calibration, it must be documented in the calibration records.
Instrument controls of the flaw-detector units shall be calibrated in accordance with the agency's quality programme
If a recorder display is used, the linearity of its scale shall also be calibrated in accordance with the agency's quality programme
Instrument readouts for determining rotational speed and linear or inspection-mechanism speed if used to monitor coverage shall also be calibrated in accordance with the agency's quality programme
Calibration must be documented on the A-scan display instrument or recorder, as well as in a log This documentation should include the calibration date, the due date for the next calibration, and the initials of the individual who performed the calibration.
Electromagnetic inspection units
Ammeters that measure magnetizing current must be calibrated according to the agency's quality program Calibration results should be documented on the ammeter itself, and a log must be kept to track the calibration of the ammeter, coil, and reference standards This log should include the calibration date, the due date for the next calibration, and the initials of the individual who performed the calibration.
Coils must be inspected to ensure the integrity of their internal wire turns, following the agency's quality program This verification is usually performed by comparing the current resistance or magnetic flux values to the original measurements taken when the coil was new.
The verification check shall be recorded in a log with the date of the calibration check, the due date and the initials of the person who performed the check
9.6.3 Rotational and linear speed instruments
Instrument readouts for determining rotational speed and linear or inspection-mechanism speed if used to monitor coverage shall also be calibrated in accordance with the agency's quality programme
Each reference indicator for standards with multiple indicators should exhibit a similar response, averaging around 10% This response must be verified during manufacturing and at least once every specified interval.
10 Drill stem element inspection and classification
Pipe body — Full-length visual inspection
A comprehensive visual inspection of the entire external surface, from upset to upset, will be performed to identify any visible defects such as gouges, cuts, pits, dents, crushing, necking, string shot, grinding, bent pipe, and other imperfections Additionally, the internal surfaces will be examined from both ends to check for pits, erosion, and wireline cuts, along with an assessment of the condition of any existing internal coating.
Inspected areas must be thoroughly clean and devoid of dirt, thread dope, grease, rust, loose paint, lint, and any other foreign materials that could hinder the inspection process and compromise accuracy.
A non-permanent marker like chalk can be utilized to mark areas that need assessment or may produce indications during electromagnetic inspection Additionally, an illumination source that complies with the specifications of section 9.3 is necessary.
External illumination shall meet the requirements of 9.3
Each pipe must undergo a thorough visual inspection of its entire outer surface to identify any imperfections This inspection can be performed independently or alongside outer diameter (OD) gauging It is essential to roll each length of pipe to ensure a complete view of the surface and to check for any visually detectable flaws.
While illuminating the inside surface, visually examine the internal surface from each end, noting any visually detectable imperfections and the condition of the internal coating
All external imperfections shall be marked with non-permanent markings to allow easy and quick correlation when it is detected by the electronic inspection
Imperfections detected that can affect the classification shall be marked and evaluated according to 10.13, based on the type of imperfection
The internal coating's condition should be assessed by estimating the percentage that is either missing or not bonded to the pipe However, this evaluation does not serve as a basis for classifying the pipe.
The condition of the internal coating of the drill pipe does not influence its operational limits and is therefore excluded from the classification criteria Any reported conditions are provided to the owner solely for informational purposes.
Pipes that are bent or bowed more than 76 mm (3.0 in) along their entire length, or more than 12.7 mm (0.5 in) within the first 1.5 m (5.0 ft) from either end, are not subject to inspection Additionally, all lengths that have undergone straightening must be inspected following the straightening process.
Pipe shall not be inspected with drill-pipe rubbers installed
10.2 Drill body — Outside diameter gauging
Each length of pipe must be inspected from upset to upset using an OD gauge to detect any diameter reductions The pipe should be rolled while the OD gauge is moved along its surface For every 1.5 m (5.0 ft) section inspected, the pipe must be rotated a complete 360° Acceptable measurement methods for the outer diameter include laser, vision systems, or other techniques, provided they meet the minimum requirements outlined in section 10.2.
The OD gauge is a go/no-go tool designed to identify reductions in the pipe's outside diameter, with detection anvils set 0.79 mm (0.031 in) smaller than the specified diameter If the gauge fails to fit over the pipe, it indicates that the diameter reduction is less than 0.79 mm (0.031 in) This tool allows for a quick scan of the pipe to pinpoint areas where the outside diameter is reduced by 0.79 mm (0.031 in) or more Additionally, a caliper is necessary to measure the length of the standardization bar.
The outside diameter of the drill-pipe body shall be cleaned to remove scale, mud, etc Cleaning is done only as required to properly perform the OD gauging
To verify the standardization bar length, use callipers to ensure it measures 0.79 mm ± 0.13 mm (0.031 in ± 0.005 in) less than the specified outside diameter of the pipe, as referenced in Tables C.4 or C.5 (or D.4 or D.5) Check and adjust the anvils with the standardization bar, ensuring they are parallel and that the bar fits snugly at both ends Confirm that all screws are tightened, and if a wire indicator is available, adjust it by placing the standardization bar over the plunger and setting the indicator to the correct measurement.
General standardization of inspection equipment shall be performed at the beginning of each job
Periodic standardization checks must be conducted at the start of each inspection shift and after breaks, at least once every hour of continuous operation or after every 25 lengths inspected, whichever comes first Additionally, checks are required whenever there is a change in the operator, after the OD gauge experiences abnormal mechanical shock, before breaks during a job, prior to resuming operations after repairs or adjustments, and before shutting down equipment at the end of the job.
All pipe inspected between an unacceptable check and the most recent acceptable check shall be re-inspected
Each length of pipe must undergo OD gauging along its entire length, from upset to upset The pipe should be rolled at least 180° for every 0.8 m (2.5 ft) of gauging, and it is essential to ensure that all anvils of the OD gauge remain secure throughout the process.
To accurately measure the pipe's outside diameter, ensure the anvil opposite the plunger is firmly pressed against the pipe surface before taking a reading Rotate the pipe a complete 180° to identify the maximum reading, and examine both sides of the initial position along the pipe axis to detect the greatest reduction in outside diameter.
Mark the location of the maximum reduction in outside diameter by placing an "X" next to each parallel anvil Assess whether this reduction is caused by wear or by mechanical deformation due to stress.
If the outside diameter reduction is due to wear, the evaluation for classification shall be based on the remaining wall thickness as specified in 10.13.5
10.2.7 Stress-induced diameter reductions or increases
If the outside diameter reduction is stress-induced (crushing, necking, dents or mashes), it shall be evaluated in accordance with the procedures for stress-induced diameter reduction in 10.13.6
If an outside diameter increase is detected (string shot), it shall be evaluated in accordance with procedures for stress-induced diameter increases in 10.13.7.
Pipe body — Ultrasonic wall-thickness gauging
Manual ultrasonic wall-thickness measurements are conducted to assess the minimum wall thickness at the center of a pipe or at points indicated by OD gauges or other instruments showing wall reduction Typically, this test is performed at a single location on drill pipes, although it may also be carried out at additional sites as needed.
The ultrasonic thickness gauge measures wall thickness from the outer surface and typically includes an ultrasonic transducer, a connecting cable, and a battery-powered instrument with a digital, scope, or meter readout The dual-element transducer must have a diameter not exceeding 9.53 mm (0.375 in) and should accurately read the thickness of a parallel-surface test block within 0.025 mm (0.001 in) of the actual thickness Additionally, when measuring remaining wall thickness above an internal imperfection, it must comply with the sensitivity requirements outlined in section 9.5.1.2.
A couplant is essential for wetting the pipe surface and facilitating the transmission of ultrasound from the transducers during testing It must be free of contaminants that could affect inspection sensitivity or readout interpretation While rust inhibitors, water softeners, glycerine, antifreeze, or wetting agents can be added, they should not harm the pipe surface Additionally, the couplant should have adequate viscosity to ensure an air-free interface without requiring excessive pressure on the transducer.
For optimal transducer placement, surfaces must be thoroughly cleaned and devoid of any loose scale, dirt, grease, or other materials that could disrupt the zeroing process on the pipe surface, compromise inspection sensitivity, or affect the accuracy of the readout interpretation.
Ultrasonic thickness gauges shall be calibrated as required in 9.5.1
If the readout fluctuates while the transducer is firmly positioned on the test block, it indicates a malfunction in the gauge The device must be repaired or replaced before proceeding with standardization or inspection.
For effective standardization, all standards must exhibit velocity and attenuation properties akin to the inspected material To reduce errors caused by temperature variations, it is essential to acclimate the standards to the same ambient temperature as the material for at least 30 minutes However, placing the standard directly on the pipe surface and maximizing contact area can reduce this exposure time to just 10 minutes.
The parting line of the transmitting and receiving transducer must be perpendicular to the axis of the standard or pipe If a dual-element transducer's parting line is positioned at an angle less than perpendicular to the longitudinal axis, it can lead to ultrasonic readings that exceed the actual pipe thickness This error increases with smaller pipe diameters.
Reference standards must match the external surface curvature of the specified outside diameter of the material being measured However, for pipes with specified diameters greater than 88.93 mm (3 1/2 in), a flat standard may be utilized.
All gauges must be standardized following the manufacturer's instructions, using a standard thickness that is at least 1.27 mm (0.050 in) thinner than the minimum wall thickness for class 2, and a second standard thickness that is at least 1.27 mm (0.050 in) thicker than the specified wall thickness of the material being inspected The standard thickness must be verified using a micrometer, and the gauge accuracy should be within 0.025 mm (0.001 in) of the standard thickness for both required thickness steps.
When standardizing reference standards with different outside surface curvatures than the specified outside diameter of the measured material, it is essential to verify the ultrasonic zero on a known thickness curved piece, like the EMI reference standard.
A concave transducer face can lead to inaccurate thickness readings in pipes, making the wall appear thinner or thicker depending on the curvature of the standard used for calibration To ensure accurate measurements, it is crucial to maintain a flat transducer face, as wear and diameter variations can affect performance Prior to inspection, the transducer should be checked for wear by comparing its accuracy against both curved and flat reference standards with the same velocity If the transducer shows no signs of wear, the readings will be reliable; however, any worn transducers must be replaced to maintain measurement accuracy.
Periodic standardization checks must be conducted at key intervals to ensure accurate measurements and system performance These checks should occur at the start of each inspection shift, after every 25 areas measured in continuous operations, following any power interruptions or changes in power supply, and whenever there is a change in the operator Additionally, checks are necessary before equipment shutdown, after repairs or changes to system components, when there is a change in transducer, cable, or couplant, before turning off the gauge at the end of a job, and whenever readings are within 0.25 mm (0.010 in) of the minimum permissible remaining wall thickness prior to downgrade.
During a standardization check, if the gauge reading deviates by more than 0.05 mm (0.002 in) from the original standardization value, it must be readjusted Additionally, all drill pipes inspected between an unacceptable check and the latest acceptable check are required to undergo re-inspection.
10.3.6 Manual ultrasonic thickness-gauging procedure
To ensure accurate assessment of wall thickness, multiple measurements should be taken around the pipe to identify the minimum thickness in areas of reduction, as indicated by the OD gauge or other inspection methods If no such indications are present, measurements should be taken approximately at the center of the drill-pipe tube to determine the minimum wall thickness.
In each area being measured, remove all dirt and loose material that can interfere with the accuracy of the wall- thickness measurement from the external surface and apply a couplant
Ensure that each measurement reading stabilizes before comparing it to the minimum allowable wall thickness A reading is considered stable if it remains constant at 0.025 mm (0.001 in) for a duration of at least 3 seconds.
Pipe body — Full-length electromagnetic inspection (EMI)
Flux-leakage detection equipment employs a strong magnetic field around the pipe to generate a leakage field when properly aligned discontinuities exist The sensors discussed in this article are designed to identify magnetic-flux leakage fields on the external surface of the pipe, specifically at sites of transverse and volumetric defects.
ISO 10407 specifies EMI equipment for detecting flux leakage, which employs search coils or Hall-effect sensors This equipment identifies imperfections by either passing a magnetized pipe through a stationary encircling scanner or by moving the encircling sensors along the length of the magnetized pipe.
The inspection assembly shall be sized according to the size of pipe being inspected
The outer diameter of the pipe, from upset to upset, must be thoroughly cleaned to eliminate any scale, mud, or coatings that could hinder the movement of the detector ride and the pipe inspection assembly.
Electromagnetic inspection units, coils and reference standards shall be calibrated as required in 9.6
EMI reference standards are essential for ensuring uniform sensitivity across all detectors, although specific dimensions and wall thicknesses are not defined The surface conditions of the reference standard must comply with section 10.4.3, and it should match the outside diameter of the pipe being inspected Reference standards can feature one or more reference indicators, typically consisting of 1.5 mm (1/16 in) through-wall drilled holes When multiple holes are present, they must be spaced to allow for independent visibility of each indication, and these multi-hole reference standards should be verified according to section 9.6.4.
The reference standard must be inspected at production speed to generate a reference signal from each detector, necessitating multiple passes for a single reference indicator standard Instrumentation should be calibrated to ensure an indication amplitude of at least 25% of full scale, clearly distinguishable from background noise for each detector Additionally, all detectors must be set to the same signal level, which is 10% of the average amplitude, as full-scale indicators are prohibited to accurately determine positive variances.
Equipment shall provide a minimum signal-to-noise ratio (S/N) of 3 to 1 for reference indicators
General standardization of EMI inspection equipment shall be performed at the beginning of each job
Periodic standardization checks must be conducted at the start of each inspection shift, after every 50 lengths measured in continuous operations, following any power interruption, before shutting down equipment during a job, and before resuming operations after repairs or changes to system components that may impact performance Additionally, checks are required whenever there are changes to the detector, connector, or current settings, as well as prior to the final equipment shutdown at the end of the job.
During each inspection of the reference standard, all signals must remain within 20% of the standardization amplitude If a periodic check fails to meet this criterion, all pipes inspected between the last acceptable check and the unacceptable one must undergo re-inspection.
10.4.6.1 Travelling-head unit on drill pipe
When utilizing travelling-head inspection assemblies, it is essential to ensure that the tool joints at both ends of the pipe are adequately inspected, unless a system-capability demonstration proves that full coverage of the pipe body is unnecessary Position the inspection head approximately 0.91 m (3 ft) from the near tool joint, then place the coil over the travelling head to inspect the last 0.91 m (3 ft) by moving the head towards the tool joint until it halts After this, reverse the travelling head, reposition the coil, and conduct the inspection towards the far tool joint until it is stopped by that joint.
When using a stationary unit, pass each length through the EMI inspection unit
If the speed varies by more than 10 % from the standardization speed, the area in question shall be re-inspected at the proper speed
A threshold for signal amplitude must be set according to the agency's standard operating procedures and should not exceed the reference level Any signals that surpass this threshold must be identified and marked on the external surface for the entire length of each indication All marked indications should be evaluated in accordance with section 10.13.
A readout of imperfection indications detected and a record of the inspection shall be made and identified These documents shall be retained by the agency for a minimum of one year
In most cases, a one-year record retention period is adequate However, if extended retention is necessary, specific requirements must be established between the owner/operator and the agency.
Pipe body — Full-length ultrasonic transverse and wall thickness
Section 10.5 outlines the equipment requirements and procedures for conducting ultrasonic inspections on used drill-pipe bodies, specifically between the pipe upsets This inspection aims to identify transverse imperfections on both the internal and external surfaces of the pipe, while also monitoring the wall thickness throughout the inspected area.
The ultrasonic instrument must be a pulse-echo type featuring an A-scan presentation, with gain control increments limited to 0.5 dB It should include both audible and visual alarms, and be equipped with either a strip chart recorder or a digital data-acquisition-and-display system for capturing and storing inspection data The display system must allow for individual information display from each transducer orientation Additionally, any available reject control should only be utilized if it can be proven not to impact linearity.
Transducer frequency between 2,25 MHz and 10,0 MHz should be used
The couplant must ensure effective acoustic contact between the transducer beams and the pipe surface, which should be free of contaminants that could affect inspection sensitivity and readout interpretation Additives like rust inhibitors, water softeners, glycerine, antifreeze, or wetting agents may be included in the couplant, as long as they do not harm the pipe surface Additionally, a method for monitoring effective acoustic coupling should be implemented.
Separate sound beams will be utilized to detect both transverse and wall thickness The effective combination of linear and rotational speeds of the material or scanner will ensure 100% full-body coverage, determined by the effective beam width (EBW) of the transducer and the pulse density (PD) for each instrument channel The material can be pre-wet or fully submerged during scanning, with the couplant ensuring effective acoustic contact between the transducer beams and the pipe surface The agency will define the EBW and PD parameters.
Shear-wave sound beams are directed longitudinally to detect imperfections that are oriented transversely to the major axis, allowing for the identification of three-dimensional flaws like cracks and pits Additionally, compression-wave sound beams, which are propagated perpendicular to the material surface, are utilized to accurately measure wall thickness.
All drill pipe surfaces must be thoroughly cleaned to eliminate loose scale, dirt, grease, or any other substances that could affect the sensitivity of the inspection and the accuracy of the readout interpretation.
Ultrasonic flaw-detector units shall be calibrated as required in 9.5.2
The sensors and readout of equipment used to verify coverage (rollers, rotators, etc.) shall be calibrated every six months
Displays associated with gain (dB) controls shall be calibrated for linearity at least every six months
The reference standard must be adequately long for regular dynamic checks and should match the specified outside diameter, wall thickness, and acoustical properties of the pipe under inspection.
The reference standard must include both internal and external transverse surface notches These reference notches for standardization should adhere to specific criteria: a maximum length of 12.7 mm (0.5 in), a maximum depth of 5% of the specified wall thickness, and a maximum width of 1.0 mm (0.040 in).
The impact of reference notches on signal amplitude will be assessed by comparing the peak amplitudes from both sides of the reflector It is essential that the amplitude from one side of the notch is at least 79% (2 dB) of the amplitude from the opposite side.
New drill pipes must be produced in accordance with ISO 11961 standards The 5% notch requirement for used drill pipes, as outlined in ISO 10407, is designed to improve the detection of fatigue cracks By standardizing the 5% notch, indications can be deemed acceptable based on the criteria set forth in ISO 11961.
Notches shall be separated such that the indication from each is distinct and separate from the others and from other anomalies or end effects
The wall-thickness standard can exist as a standalone guideline or be integrated into the notched standard It must include at least two thickness measurements that facilitate the adjustment of readings across a suitable range for the material under inspection These reference thicknesses should be confirmed using a micrometer or a standardized ultrasonic thickness gauge One measurement must be equal to or exceed the specified wall thickness of the inspected tube, while the other must be less than 70% of that specified thickness Additionally, the equipment's wall thickness readout should be calibrated to reflect the reference thicknesses within 0.25 mm (0.010 in) or 2% of the specified wall thickness, depending on which value is smaller.
The A-scan display range shall be adjusted to at least one-and-a-half skips
Instrumentation must be calibrated to generate reference signal amplitudes of at least 60% of the full scale for each transducer Additionally, the signal from each transducer should vary within 10% of the average signal height for all transducers aligned in the same orientation.
A threshold will be set based on the agency's standard operating procedures, ensuring it does not exceed 60% of the reference level The gates on both the inside and outside surfaces will be strategically placed to fully encompass the signals received from their respective areas.
Equipment gain and threshold adjustments shall ensure a minimum signal-to-noise ratio (S/N) of 3 to 1
On rotating systems, the helix shall be sufficient so that all signals are repeatable within two decibels on repeated passes
A dynamic standardization check will be conducted to ensure consistency by inspecting the reference standard at production speeds twice consecutively If the notch amplitude from one run is below 79% (2 dB) of the amplitude from the other run of the same orientation and notch type, adjustments will be made to the system, followed by a repeat of the dynamic standardization process.
Standardization of ultrasonic inspection equipment is essential and must be conducted at the start of each job Additional standardization checks are required at the beginning of each inspection shift, every 4 hours of continuous operation or after inspecting 50 lengths for mechanized units, following any power interruption, before shutting down equipment during a job, after repairs or changes to system components affecting performance, whenever a transducer or cable is replaced, and before shutting down at the end of the job.
Pipe body — Full-length ultrasonic transverse, wall thickness and longitudinal inspection
Section 10.6 outlines the equipment requirements and procedures for conducting ultrasonic inspections on the used drill-pipe tube body, specifically between the upsets This inspection aims to identify both transverse and longitudinal imperfections on the inner and outer surfaces of the pipe Furthermore, the inspection system is designed to continuously monitor the wall thickness throughout the entire inspected area.
The ultrasonic instrument must be a pulse-echo type featuring an A-scan presentation, with gain-control increments limited to a maximum of 0.5 dB It should include both audible and visual alarms, and be equipped with either a strip-chart recorder or a digital data-acquisition-and-display system for capturing and storing inspection data The display system must allow for individual information display from each transducer orientation Additionally, any available reject control should only be utilized if it can be proven not to impact linearity.
A transducer frequency between 2,25 MHz and 10,0 MHz should be used
The couplant must ensure effective acoustic contact between the transducer beams and the pipe surface, which should be free of contaminants that could affect inspection sensitivity and readout interpretation Additives like rust inhibitors, water softeners, glycerine, antifreeze, or wetting agents can be included in the couplant, provided they do not harm the pipe surface Additionally, a method for monitoring effective acoustic coupling should be implemented.
Separate sound beams are utilized to detect transverse, longitudinal, and wall thickness variations The combination of the material's linear and rotational speed with the scanner ensures complete 100% full-body coverage, determined by the effective beam width (EBW) of the transducer and the spacing of successive pulses for each instrument channel Scanning can be performed on materials that are pre-wet or partially or fully submerged An effective couplant is essential for ensuring proper acoustic contact between the transducer beams and the pipe surface, with the EBW and pulse duration (PD) specified by the governing agency.
Shear-wave sound beams are generated in both clockwise and counter-clockwise directions by multiple transducers This system's sensitivity allows for the detection, display, and recording of imperfections aligned with the major axis, including seams, laps, and cracks.
The angle of the sound beam chosen for inspection shall ensure intersection with the material inside surface
Shear-wave sound beams are directed along longitudinal paths to detect imperfections that are oriented transversely to the major axis This system's high sensitivity allows for the detection, display, and recording of various three-dimensional imperfections, including cracks and pits.
Compression-wave sound beams propagated normal to the materials surface are used to measure wall thickness
To ensure accurate inspection results, all drill-pipe surfaces must be thoroughly cleaned to eliminate loose scale, dirt, grease, and any other materials that could affect the sensitivity of the inspection and the interpretation of the readout.
Ultrasonic flaw detector units shall be calibrated as required in 9.5.2
Sensors and readout equipment used to verify coverage (rollers, rotators, etc.) shall be calibrated every six months
Displays associated with gain (dB) controls shall be calibrated for linearity at least every six months
A reference standard must be adequately sized for regular dynamic assessments and should match the specified outside diameter, wall thickness, and acoustic characteristics of the pipe being inspected.
A reference standard must include both internal and external transverse and longitudinal notches For standardization, these reference notches should adhere to specific criteria: a maximum length of 12.7 mm (0.5 in), a maximum depth of 5% of the specified wall thickness for pipes, and a maximum width of 1.0 mm (0.040 in).
The impact of reference notches on signal amplitude will be assessed by comparing the peak amplitudes from both sides of the reflector It is essential that the amplitude from one side of the notch is at least 79% (2 dB) of the amplitude from the opposite side.
New drill pipes must be produced in accordance with ISO 11961 standards The 5% notch requirement for used drill pipes, as outlined in ISO 10407, is designed to improve the detection of fatigue cracks By standardizing the 5% notch, indications can be deemed acceptable under ISO 11961 criteria.
Notches shall be separated such that the indication from each is distinct and separate from the others and from other anomalies or end effects
The wall-thickness standard can exist as a standalone guideline or be integrated into the notched standard It must include at least two thickness measurements that facilitate the adjustment of readings across a suitable range for the material under inspection These reference thicknesses should be confirmed using a micrometer or a standardized ultrasonic thickness gauge One measurement must be equal to or exceed the specified wall thickness of the inspected tube, while the other must be less than 70% of that specified thickness Additionally, the equipment's wall thickness readout should be calibrated to reflect the reference thicknesses within 0.25 mm (0.010 in) or 2% of the specified wall thickness, depending on which value is smaller.
The A-scan display range shall be adjusted to at least one-and-a-half skip
Instrumentation must be calibrated to generate reference-signal amplitudes of at least 60% of the full scale for each transducer Additionally, the signal from each transducer should vary within 10% of the average signal height for all detectors aligned in the same orientation.
Equipment gain and threshold adjustments shall ensure a minimum signal-to-noise ratio (S/N) of 3 to 1
On rotating systems, the helix shall be sufficient so that all signals are repeatable within 2 dB on repeated passes
A dynamic standardization check will be conducted to ensure consistency by inspecting the reference standard at production speeds twice consecutively If the notch amplitude from one run is below 79% (2 dB) of the amplitude from the other run of the same orientation and notch type, adjustments will be made to the system, followed by a repeat of the dynamic standardization process.
Standardization of ultrasonic inspection equipment shall be performed at the beginning of each job
Standardization checks must be conducted at specific intervals to ensure optimal performance These checks should occur at the start of each inspection shift, at least every four hours during continuous operation or after inspecting 50 lengths for mechanized units, following any power interruption, before shutting down equipment during a job, and before resuming operations after repairs or changes to system components Additionally, checks are required whenever a transducer or cable is replaced or adjusted, and before shutting down equipment at the end of the job.