Non-magnetic Drill Collar
Non-magnetic Drill collars are made from Non-magnetic drill collar materials with low- strength (SWNM20-14) by combining a proprietary chemical analysis and a rotary hammer forging process with low magnetic permeability excellent machine ability. The material is resistant to stress corrosion cracking, with high machine ability and no tendency to galling.
Each drill collar is fully inspected by internal inspection dept. Strict to control of chemical composition and special forging process guarantee the excellent mechanical properties of SENWELL’S non-magnetic tools.
Non magnetic Properties:
Relative Permeability: Max1.005
Hot spot/Field Gradient△ B: Max ± 0.05μT
When MPS=1 ×105/4πA/m:
Special Treatment on ID: Roller Burnishing (After roller burnishing, a compressive layer come into being)
Advantage:
a.) Increase the corrosion resistance properties
b.) Increase the surface hardness of bore up to HB400
c.) Increase surface finished of bore to Ra≤3.2μm
Inspection& test items for each Non-magnetic drill collar, non-magnetic stabilizer etc.
Chemical composition, Tensile Test, Impact Test, Hardness Test, Metallographic Test (Grain Size), Corrosion Test (according to ASTM A262 Practice E), Ultrasonic Test over the whole length of the bar (according to ASTM A388), Relative Magnetic Permeability Test, Hot Spot Test, Dimension Test etc.
Drill collars are available in lengths from 10 to 31 feet and outside diameter from 3 1/8” to 11".
Mechanical Properties
Steel Grade |
OD Range (in) |
Yield Strength
Rt |
Tensile Strength
Rm |
Elongation
A |
Impact Value |
Hardness
Brinell |
Mpa |
ksi |
Mpa |
ksi |
(%) |
(Akv) |
(HB) |
NM-1 |
3 1/8”~6 7/8” |
≥758 |
≥110 |
≥827 |
≥120 |
≥25 |
≥150
Longitudinal |
285-360 |
7”~11” |
≥689 |
≥100 |
NM-2 |
3 1/8”~6 7/8” |
≥827 |
≥120 |
≥896 |
≥130 |
≥25 |
≥150
Longitudinal |
285-360 |
7”~11” |
≥758 |
≥110 |
NM-3 |
3 1/8”~6 7/8” |
≥965 |
≥140 |
≥1034 |
≥150 |
≥20 |
≥90
Longitudinal |
330-400 |
7”~11” |
≥896 |
≥130 |
NM-4 |
3 1/8”~6 7/8” |
≥827 |
≥120 |
≥896 |
≥130 |
≥20 |
≥75
Longitudinal |
285-360 |
7”~11” |
≥785 |
≥110 |
Technical specifications and parameters for Non-magnetic Drill Collars |
OD |
ID |
Length (mm) |
Bevel diameter (mm) |
Connection |
Bending strength ratio |
in |
mm |
in |
mm |
3-1/8 |
79.4 |
1-1/4 |
31.8 |
9150 |
76.2 |
NC23-31 |
2.57:1 |
3-1/2 |
88.9 |
1-1/2 |
38.1 |
9150 |
82.9 |
NC26-35 (2 3/8IF) |
2.42:1 |
4-1/8 |
104.8 |
2 |
50.8 |
9150 |
100.4 |
NC31-41 (2 7/8IF) |
2.43:1 |
4-3/4 |
120.7 |
2 |
50.8 |
9150 |
114.7 |
NC35-47 |
2.58:1 |
5 |
127 |
2-1/4 |
57.2 |
9150 |
121.0 |
NC38-50 (3 1/2IF) |
2.38:1 |
6 |
152.4 |
2-1/4 |
57.2 |
9150/9450 |
144.5 |
NC44-60 |
2.49:1 |
6 |
152.4 |
2-13/16 |
71.4 |
9150/9450 |
144.5 |
NC44-60 |
2.84:1 |
6-1/4 |
158.8 |
2-1/4 |
57.2 |
9150/9450 |
149.2 |
NC44-62 |
2.91:1 |
6-1/4 |
158.8 |
2-13/16 |
71.4 |
9150/9450 |
150.0 |
NC46-62 (4IF) |
2.63:1 |
6-1/2 |
165.1 |
2-1/4 |
57.2 |
9150/9450 |
154.8 |
NC46-65 (4IF) |
2.76:1 |
6-1/2 |
165.1 |
2-13/16 |
71.4 |
9150/9450 |
154.8 |
NC46-65 (4IF) |
3.05:1 |
6-3/4 |
171.4 |
2-1/4 |
57.2 |
9150/9450 |
159.5 |
NC46-67 (4IF) |
3.18:1 |
6-3/4 |
171.4 |
2-13/16 |
71.4 |
9150/9450 |
159.5 |
NC50-67 (41/2IF) |
2.37:1 |
7 |
177.8 |
2-1/4 |
57.2 |
9150/9450 |
164.7 |
NC50-70 (41/2IF) |
2.54:1 |
7 |
177.8 |
2-13/16 |
71.4 |
9150/9450 |
164.7 |
NC50-70 (41/2IF) |
2.73:1 |
7-1/4 |
184.2 |
2-13/16 |
71.4 |
9150/9450 |
169.5 |
NC50-72 (4 1/2IF) |
3.12:1 |
7-3/4 |
196.8 |
2-13/16 |
71.4 |
9150/9450 |
185.3 |
NC56-77 |
2.70:1 |
8 |
203.2 |
2-13/16 |
71.4 |
9150/9450 |
190.1 |
NC56-80 |
3.02:1 |
8-1/4 |
209.6 |
2-13/16 |
71.4 |
9150/9450 |
195.7 |
6 5/8REG |
2.93:1 |
9 |
228.6 |
2-13/16 |
71.4 |
9150/9450 |
212.7 |
NC61-90 |
3.17:1 |
9-1/2 |
241.3 |
3 |
76.2 |
9150/9450 |
223.8 |
7 5/8REG |
2.81:1 |
9-3/4 |
247.6 |
3 |
76.2 |
9150/9450 |
232.6 |
NC70-97 |
2.57:1 |
10 |
254 |
3 |
76.2 |
9150/9450 |
237.3 |
NC70-100 |
2.81:1 |
11 |
279.4 |
3 |
76.2 |
9150/9450 |
266.7 |
8 5/8REG |
2.84:1 | |
|