General
The drill
collar, mainly
used for providing
drill pressure, is
manufactured in
accordance with
API Spec 7 and API
RP 7G. The
material of
standard drill
collar is AISI
41545H. Trace
elements such as
sulfur and
phosphorus are
reduced during the
steel making
process, thus
making the
material get high
physical
properties.
Nonmagnetic
drill collar is
made from chrome
manganese, low
carbon austenitic
alloy obtained by
combining a
proprietary
chemical analysis
and a rotary
hammer forging
process. The
material is
resistant to
stress corrosion
cracking, with
high mechanical
properties, low
magnetic
permeability,
excellent
mechanical
machining
properties and no
tendency to
galling.
Product type
• Standard drill
collar
• Special spiral
collar
• Standard
nonmagnetic drill
collar
Basic Technical
Parameters of
Drill Collar
| Size
OD |
Bore
ID |
Connection
type &
size |
Length |
Bending-strength
ratio |
Weight |
| in |
mm |
in |
mm |
m |
ft |
kg/9.14m |
lb/30ft |
| 3-1/8 |
79.4 |
1-1/4 |
31.8 |
NC23 |
9.14 |
30 |
2.57:1 |
300 |
622 |
| 3-1/2 |
88.9 |
1-1/2 |
38.1 |
NC26 |
9.14
or 9.45 |
30
or 31 |
2.42:1 |
367 |
809 |
| 4-1/8 |
104.8 |
2 |
50.8 |
NC31 |
9.14 or
9.45 |
30 or 31 |
2.43:1 |
476 |
1, 030 |
| 4-3/4 |
120.7 |
2 |
50.8 |
NC35 |
9.14
or 9.45 |
30
or 31 |
2.58:1 |
681 |
1,
502 |
| 5 |
127 |
2-1/4 |
57.2 |
NC38 |
9.14 or
9.45 |
30 or 31 |
2.38:1 |
722 |
1, 592 |
| 6 |
152.4 |
2-1/4 |
57.2 |
NC44 |
9.14
or 9.45 |
30
or 31 |
2.49:1 |
1,
169 |
2,
578 |
| 6 |
152.4 |
2-13/16 |
71.4 |
NC44 |
9.14 or
9.45 |
30 or 31 |
2.84:1 |
1, 056 |
2, 328 |
| 6-1/4 |
158.8 |
2-1/4 |
57.2 |
NC44 |
9.14
or 9.45 |
30
or 31 |
2.91:1 |
1,
281 |
2,
825 |
| 6-1/4 |
158.8 |
2-13/16 |
71.4 |
NC46 |
9.14 or
9.45 |
30 or 31 |
2.63:1 |
1, 160 |
2, 558 |
| 6-1/2 |
165.1 |
2-1/4 |
57.2 |
NC46 |
9.14
or 9.45 |
30
or 31 |
2.76:1 |
1,
383 |
3,
050 |
| 6-1/2 |
165.1 |
2-13/16 |
71.4 |
NC46 |
9.14 or
9.45 |
30 or 31 |
3.05:1 |
1, 277 |
2, 816 |
| 6-3/4 |
171.5 |
2-1/4 |
57.2 |
NC46 |
9.14
or 9.45 |
30
or 31 |
3.18:1 |
1,
520 |
3,
352 |
| 7 |
177.8 |
2-1/4 |
57.2 |
NC50 |
9.14 or
9.45 |
30 or 31 |
2.54:1 |
1, 647 |
3, 632 |
| 7 |
177.8 |
2-13/16 |
71.4 |
NC50 |
9.14
or 9.45 |
30
or 31 |
2.73:1 |
1,
548 |
3,
413 |
| 7-1/4 |
184.2 |
2-13/16 |
71.4 |
NC50
|
9.14 or
9.45 |
30 or 31 |
3.12:1 |
1, 675 |
3, 693 |
| 7-3/4 |
196.9 |
2-13/16 |
71.4 |
NC56 |
9.14
or 9.45 |
30
or 31 |
2.70:1 |
1,
957 |
4,
315 |
| 8 |
203.2 |
2-13/16 |
71.4 |
NC56 |
9.14 or
9.45 |
30 or 31 |
3.02:1 |
2, 112 |
4, 657 |
| 8-1/4 |
209.6 |
2-13/16 |
71.4 |
6-5/8
REG |
9.14
or 9.45 |
30
or 31 |
2.93:1 |
2,
252 |
4,
966 |
| 9 |
228.6 |
2-13/16 |
71.2 |
NC61 |
9.14 or
9.45 |
30 or 31 |
3.17:1 |
2, 746 |
6, 055 |
| 9-1/2 |
241.3 |
3 |
76.2 |
7-5/8
REG |
9.14
or 9.45 |
30
or 31 |
2.81:1 |
3,
041 |
6,
705 |
| 9-3/4 |
247.7 |
3 |
76.2 |
NC70 |
9.14 or
9.45 |
30 or 31 |
2.57:1 |
3, 224 |
7, 109 |
Notes: 1We
can supply drill
collar with other
outside and inside
diameters
according to
customers'
requirements;
2 We can supply
drill collar made
from other
standard material,
e.g. AISI 4145HM
or AISI 4145M;
3 The premium
thread connection
such as PAC is
available.
• When ordering or
inquiring, please
specify:
• Outside and
inside diameter
• Length and
tolerance
• Size, type and
location of
connections
• Type of thread
protectors
• Slip and
elevator recess
(up to API RP 7G)
• Spiral grooves
• Stress relief
groove
• Other special
requirements
(magnets, special
mark, etc)
Nonmagnetic Drill
Collar
•
Material Features
| Magnetic
permeability
(Magnetic
intensity=
1×105/4
п Nm) |
Magnetic
gradient (Hot
point) |
| Max Value:
1.010 |
Average
Value: µ =
1.005 |
Max
Value: ΔB =
0.05 |
•
Mechanical
Properties
| Outside
diameter range |
Min
yield strength |
Min
tensile
strength |
Min
elongation |
Reduction
of area |
Charpy
impact value |
| in |
mm |
MPa |
psi |
MPa |
psi |
% |
% |
N⋅m |
lb⋅ft |
| 3-1/8-6-7/8 |
79.4-174.6 |
758 |
110,
000 |
827 |
120,
000 |
25 |
50 |
68 |
50 |
| 7-11 |
177.8-279.4 |
689 |
100, 000 |
758 |
110, 000 |
25 |
50 |
68 |
50 |
Notes:
Other nonmagnetic
products are also
available
including short
drill collar,
integral HWDP, sub
and stabilizer. |
