Drill Collars
According to API Spec.7 and SY/T5144, drill collar is made of AISI 4145 modified chromium- molybdenum alloy steel. All threads are phosphated, copperized or cold rolled , and they are machined with CNC Lathes –Double –shoulderd, including some special threads. We can supply drill collars in length from 10 to 45 feet and outside diameter from 3-1/8" to 11".The maximum outer diameter of drill collars can amount to 14”.
Mechanical property of drill collar
|
Range of outer diameter |
σ0.2 Yield intensity MPa |
σb Tensile intensity MPa |
δ4 Elongation MPa |
HB Brinell Hardness |
A Impact value J |
|
|
mm |
Inch |
|||||
|
79.4~171.4 |
3 1/8~6 3/4 |
≥758 |
≥965 |
≥13 |
≥285 |
≥54 |
|
177.8~279.4 |
7~11 |
≥689 |
≥930 |
|||
Standard size, inner diameter and threads for drill collar
|
No. |
D |
d |
L Length mm |
DF mm |
Bending intensity ratio |
||
|
Outer diameter |
Inner diameter |
||||||
|
mm |
inch |
mm |
inch |
||||
|
NC23-31 |
79.4 |
3 1/8 |
31.8 |
1 1/4 |
9150 |
76.2 |
2.57:1 |
|
NC26-35 |
88.9 |
3 1/2 |
38.1 |
1 1/2 |
9150 |
82.9 |
2.42:1 |
|
NC31-41 |
104.8 |
4 1/8 |
50.8 |
2 |
9150 or 9450 |
100.4 |
2.43:1 |
|
NC35-47 |
120.7 |
4 3/4 |
50.8 |
2 |
9150 or 9450 |
114.7 |
2.58:1 |
|
NC38-50 |
127.0 |
5 |
57.2 |
2 1/4 |
915 or 9450 |
121.0 |
2.38:1 |
|
NC44-60 |
152.4 |
6 |
57.2 |
2 1/4 |
9150 or 9450 |
144.5 |
2.49:1 |
|
NC44-60 |
152.4 |
6 |
71.4 |
2 13/16 |
9150 or 9450 |
144.5 |
2.84:1 |
|
NC44-62 |
158.8 |
6 1/4 |
57.2 |
2 1/4 |
9150 or 9450 |
149.2 |
2.91:1 |
|
NC46-62 |
158.8 |
6 1/4 |
71.4 |
2 13/16 |
9150 or 9450 |
150.0 |
2.63:1 |
|
NC46-65 |
165.1 |
6 1/2 |
57.2 |
2 1/4 |
9150 or 9450 |
154.8 |
2.76:1 |
|
NC46-65 |
165.1 |
6 1/2 |
71.4 |
2 13/16 |
9150 or 9450 |
154.8 |
3.05:1 |
|
NC46-67 |
171.4 |
6 3/4 |
57.2 |
2 1/4 |
9150 or 9450 |
159.5 |
3.18:1 |
|
NC50-67 |
171.4 |
6 3/4 |
71.4 |
2 13/16 |
9150 or 9450 |
159.5 |
2.37:1 |
|
NC50-70 |
177.8 |
7 |
57.2 |
2 1/4 |
9150 or 9450 |
164.7 |
2.54:1 |
|
NC50-70 |
177.8 |
7 |
71.4 |
2 13/16 |
9150 or 9450 |
164.7 |
2.73:1 |
|
NC50-72 |
184.2 |
7 1/4 |
71.4 |
2 13/16 |
9150 or 9450 |
169.5 |
3.12:1 |
|
NC56-77 |
196.8 |
7 3/4 |
71.4 |
2 13/16 |
9150 or 9450 |
185.3 |
2.70:1 |
|
NC56-80 |
203.2 |
8 |
71.4 |
2 13/16 |
9150 or 9450 |
190.1 |
3.02:1 |
|
6 5/8REG |
209.6 |
8 1/4 |
71.4 |
2 13/16 |
9150 or 9450 |
195.7 |
2.93:1 |
|
NC61-90 |
228.6 |
9 |
71.4 |
2 13/16 |
9150 or 9450 |
212.7 |
3.17:1 |
|
7 5/8REG |
241.3 |
9 1/2 |
76.2 |
3 |
9150 or 9450 |
223.8 |
2.81:1 |
|
NC70-97 |
247.6 |
9 3/4 |
76.2 |
3 |
9150 or 9450 |
232.6 |
2.57:1 |
|
NC70-100 |
254.0 |
10 |
76.2 |
3 |
9150 or 9450 |
237.3 |
2.81:1 |
|
8 5/8REG |
279.4 |
11 |
76.2 |
3 |
9150 or 9450 |
266.7 |
2.84:1 |
