5. DS-1 Volume 3 - 4th edition
Inspection of Drill String
consisting of a single
piece with no component
6. What are the major enhancements for DS‐1®
Fourth Edition compared to Third
Add procedures cover hard-banding
(re‐application and inspection) and tool
joint build up.
Expand dimensional and visual inspection
procedures for new proprietary
Move seven procedures covering Specialty
Tools to Volume 4.
7. Standard DS1:
■Standards for Inspection- Accepting &Rejecting
used drill Pipes.
■Drill Stem Inspection covering wide range of
■ specific Procedures & Methodology.
■ Flexible options.
■ Training & Qualifications.
■ Calibration mandatory requirement.
■Quality Control measures outlined for equipment &
10. Recommended Inspection Programs for DP (Page
The inspection program
(a)Which inspection methods will be applied to each
drill stem component.
(b)How each inspection method must be conducted
in a step-by-step procedure.
(c)What acceptance criteria will be in effect during
inspection -- that is, the user’s definition of “good”
Features covered by Inspection
11. Drill Pipe
UT Wall Thickness
Scanning MPI /Slip
UT Slip Area
Fluorescent MPI of
connection Thread profiling
w/gauge OD/ID Gauging
12. **DS1 Category 5 is intended for drill string
components that are to be used in extremely
adverse conditions where the potential cost of
failure is very large. DS1 Category 5 includes the
Ultrasonic End Area Inspection of Upset and Slip
areas of the Drill pipe, where the accumulated
fatigue at both the areas together contribute 96%
probability of failure.
16. 3.4.4 Procedure and acceptance criteria: (page32)
a.External Surface imperfection on pipe shall be measured and the
depth subtracted from average adjacent wall thickness to determine
the remaining wall thickness under the imperfection and compared to
listed in table 3.5.1 (Reject if found less than criteria)
b.Pipe with extensive raised metal in the slip area may be pulled out
without further inspection at the discretion of the inspection company
c. Raised metal on the pipe may be removed if permitted by the
customer and the owner of the pipe.
17. d.The minimum illumination level shall be 50
e.ID pitting shall not exceed 1/8” in depth as
visually estimated for premium class NWDP.
For class 2 NWDP Pitting shall not exceed 3/16”
f.The tubes shall not be visibly crooked by more
than 3” over the entire length or 0.5” in first 5”
from either end.
18. -MPI shall be done on the straightened tube
section and 2 feet in either side.
g. The ID surface of internally coated pipe shall be
examined for signs of deterioration of the coating.
-Tubes with coating Reference condition 3 or 4
shall be rejected unless waived by the
20. 3.5 OD Gage TubeInspection (Page 33)
This procedure covers the full length mechanical gaging of the tube
for outside diameter variations.
Go-no-go type gages.
Any electronic, dial, or vernierdevice.
Fixed setting standards for fielduse.
-The OD gage calibration shall be verified at the applicable maximum
and minimum OD values given in table 3.6.1 & 3.6.2.
21. 3.5.5 Procedure
a. The tube shall be gaged from upset to-
upset by dragging the gage along the tube
length while rotating the pipe.
- The pipe shall roll at least one revolution
for every 5 feet of length inspected.
b. Acceptance criteria found in Table3.6.1.
22. 3.6 UT Wall thickness inspection (Page.34)
This procedure covers the UT measurement of
DP wall thickness of the tube near the center
of the tube and at points of obvious wear.
Separate transmit and received transducer
with no worn to degree that makes visible
23. b. The same couplant shall be used in both
calibration and gaging.
c. Reference stander properties
-The same acoustic properties of pipe being
Shall have two thicknesses that meet the
• Thick section= nominal wall, +0.100, -0”
• Thin section=70%of nominal, +0, -0.100”
24. d. Minimum and maximum values of thick and
thin section found at Table 3.6.1 & 3.6.2 .
a. Parting line
Line between transmit and receive elements on
the two element transducer, It shall be held
perpendicular to the longitudinal axis of the pipe.
25. b. Readings shall be taken within one foot of the
center on each tube.
c. Readings shall be taken within 1” radius at the
lowest reading area.
Acceptance criteria found at table 3.6.1 & 3.6.2.
26. Classification of used NWDP tube:
-Dimensional acceptance criteria for used NWDP tube meet
requirements of table 1A(3.6.1-DS-1).
CONDITION PREMIUM CLASS CLASS 2
Min. remaining WT ≤ 80% ≤ 70%
Slip cuts Depth ≥ 10% of Avg. adj. Wall ≥ 20% of Avg. adj. Wall
Diameter reduction ≥ 3 % of specified OD ≥ 4 % of specified OD
Diameter Increase ≥ 3 % of specified OD ≥ 4 % of specified OD
Cracks None None
27. 3.7 Electromagnetic Inspection (EMI)(Page 35)
This procedure cover scanning for transverse
and 3D flaws using flux leakage detection
It shall be a through-wall drilled hole stander
prepared from the same nominal diameter as
the pipe to be inspected.
The hole size shall be 1/16”, +_1/64
The stander may have one hole for each
detector arranged in spiral
28. Standardization Of Flux Leakage Equipment
a.The reference amplitude shall be minimum 10 mm
from each detector.
b. Signal to noise ratio shall be 3 to1.
c.The reference stander shall be scanned four times
continually at the speed to be used for inspection.
d.Each signal channel must produce indication of at
least 80% of the reference amplitude.
e.Their shall not be any gap between detector and
29. The unit Shall be re-standardized:
At thestart of each job.
After each 50 length.
Each time the unit is turned on.
When mechanical or electronic changes or adjustments
Upon completion of the job.
If previous standardization accuracy cannot be verified all
pipe run since the last one shall be re inspected after
30. Inspection Procedure:
The permanent record should have serial number of
pipe and end from which scanning began.
Each length shall be scanned from upset-to-upset.
The head shall be propelled into the near end tool joint.
The head turned around and propelled the full length
into the opposite tooljoint.
The rate of scanning for EMI device shall be constant
for production and stander and for the entire length.
Each indication exceeding 50% of the standerreference
shall be marked until a minimum of 10 area marked.
31. How to prove up EMI Indication?
1. Visual mechanical measurements.
3. Ultrasonic (WT).
4. Other techniques as required toidentify.
The threshold level for the flux leakage unit shall not be grater
than 80% of the reference level.
The threshold level for thickness unit shall be the signal level
representing 85% of nominal wall thickness.
Pipe with imperfection which don’t meet the
acceptance criteria shall be rejected.
Areas in which flux leakage indication exceed
threshold but no imperfection can be found shall be re-
scanned and if found this shall be cause for rejection.
33. This procedure covers inspection of slip and upset
external surfaces of used DP for transfer and 3D flaws
using either dry magnetic particle with an active AC
field or wet fluorescent with an active DC field.
The area to beinspected:
1. 36” on the tube side start from 35 or 18 pin tool joint taper.(+6”
in case of additional slip cut).
2. 48” on the tube side start from 18 Box tool joint taper.(+6” in
case of additional slip cut).
3. If this method is applied on HWDP, Center pad area includes
the first 12” of tube from intersection of the transition radius
and outside tube surface on either side of the center pad.
34. Fluorescent Inspection Requirements:
1. Petroleum based medium that exhibit natural fluorescent
under black light shall not be used. (Diesel and gasoline
are not acceptable).
2. Water base medium are acceptable if they wet the
3. Particle concentration shall range from 0.1 to 0.4 ml/100
ml when measure using ASTM 100 ml centrifuge.
4. The maximum pole spacing of AC yoke during
inspection shall not exceed the distance between the
poles when all segment of the yoke are perpendicular to
35. 5.The minimum pole spacing during inspection shall be
6.Black light intensity shall be measured with an
ultraviolet meter each time it turned on, after 8 hours of
operation. The minimum intensity shall be 1000
microwatt/cm2. at 15” from light source or at the
distance to be used in inspection.
7.Intensity of ambient visible light shall be 2 foot per
candles.(50 foot candles at dry non fluorescent
8. Any crack is cause of rejection except the hairline
crack in hard-facing.(Grinding is not permitted).
37. Connection Inspection
3.11 Visual Connection Inspection
This procedure used to:
1. Determine the pipe grade.
2. Evaluate the condition of the seal.
3. Evaluate the condition of the Thread.
4. Evaluate the condition of the hard-facing.
5. Evaluate the condition of the Bevel.
6. Look for evidence of box swell and pin stretch.
40. Acceptance Criteria:
a. The grade and weight stencil shall be marked either
the pin milled slot or the pin nick.
b. Hardbanding shall extend no more than 3/16”
above the tool joint surface with no broken or
missing areas larger than 1/8” cross the major
c. All connection and tool joint shall be free of visible
cracks and heat checking.
d. The minimum illumination level at the inspection
surface shall be 50 foot candles.
e. The thread protector shall be applied and secured
with approximately 50-100 ft-lbs torque.
41. API and similar Non-Proprietary connection
a. Bevel Width: Anapproximate 45 degree OD bevel
at least 1/32” wide shall be present for the full
b. Thread surfaces:
1. Thread root shall be free from any pitting.
2. Thread surfaces shall be free from imperfections that
penetrate below the thread root, occupy more than 1-
1/2” in length along the thread helix.
3. Shall be free from imperfection that exceed 1/16” in
depth or 1/8” in diameter.
42. c. Box swell: can be checked by:
1. Place a straightedge along the longitudinal axis of
box tool joint. If a visible gab exists, the OD must be
measured. Compare the OD at the bevel to the OD
2” (+-) ½” away from bevel.(no different more than
d. Seal Surfaces:
1. Shall be free of raised metal or corrosion.
2. Any pitting of the seal that estimated to exceed
1/32” in depth.
3. Any pitting occupy more than 20% of the seal width
at any given location.
43. e. Re-facing:
1. Re-facing limits are 1/32” on any removal.
f. Pin Thread Profile:
1. No visible gab between profile and thread root more than
1/16” on no more than two thread crests.(1/32” in 4
thread acco.to APIRP7G-2)
2. Uniform flank wear estimated to be to be less than 0.010”
3. No gap between the profile and thread flanks more than
4. No stretch exceeding 0.006” in two inch measured by Pin
44. I. Box Taper:
The box taper at the back of the thread shall be at an angle of
30o (+15, -0) .(Visually Inspected).
j. Shoulder Square-ness:
Benchmark is used to inspect if there is a possible lack of
alignment. That is visually estimated to exceed 1/64”, the
connection shall be reject.
k. Pitting in Pin ID:
Pitting at ID is visually measured to be deeper than 1/8” shall
be cause for Rejection.
45. l. Shoulder Flatness:
Place a straightedge across a diameter of the tool joint face and
rotating it at least 18 degree. Any visible gab shall be cause of
47. a. Box outside Diameter (OD):
1. Shall be measured 3/8” (+-1/8”) from the shoulder.
2. Two measurements shall be taken at 90 (+-10)
3. Box shall meet the requirements of the table
2A.(3.7.1, 3.7.18, 3.7.19) at DS1.
b. Pin Inside Diameter:
1. Shall be measured under the last thread facing the
2. Shall meat the requirements of the table 2A.(3.7.1,
3.7.18, 3.7.19) at DS1.
48. c. Box Shoulder Width:
1. Shall be measured by placing the straightedge
longitudinally along the tool joint, extending past the
shoulder surface, and then measuring the shoulder
thickness from this extension to the counter-bore
(excluding ID and bevel).
2. It measure at the point of minimum thickness.
3. Shall meat the requirements of the table 2A.(3.7.1, 3.7.18,
3.7.19) at DS1.
d. Tong Space:
1. Shall measured from the bevel to the edge of hard-facing.
2. Shall meat the requirements of the table 2A.(3.7.1, 3.7.18,
3.7.19) at DS1.
49. e. Box Counter-bore Depth:
1. Depth Shall be measured (including any ID bevel)
2. Shall not be less than 9/16”.
f. Box counter-bore Diameter:
1. Shall be measured as near as possible to the
2. Shall meat the requirements of the table 2A.(3.7.1,
3.7.18, 3.7.19) at DS1.
50. g. Bevel Diameter:
Outer Diameter of the contact face of the rotary shoulder
connection. It serve two purposes:
1. Protect the outer edge of the sealing face.
2. Increase the contact pressure on seal face to minimize
leaking and separation .
Shall meat the requirements of the table 2A.(3.7.1, 3.7.18,
3.7.19) at DS1.
g. Pin Neck length:
1. The distance from the 90 degree pin shoulder to the
intersection of the flank of the first full depth thread with
the pin neck (shall bemeasured).
2. Shall not exceed 9/16”.
51. i. Thread compound and protector:
1. Acceptable connection shall be compound overall thread.
2. Thread protector shall be applied with 50-100ft-lbs of