1. Apply WOB to the drill bit;
2. Ensure the necessary strength under compression conditions;
3. Reduce the vibration, swing, and jump of the drill bit, so that the drill bit works smoothly;
4. Control well deviation
Product specifications
1) Product size 3-1/8" to 14"
2) Bar grade: 4145H; 4145H-MOD; P530; P550
3) Product type: smooth drill pipe, spiral drill collar, non-magnetic drill collar
4) Product length: 30 feet, 31 feet or according to customer special requirements
5) Thread type: from NC23 to 6-5/8REG; 7-5/8REG; 8-5/8REG; 8-5/8H90
6) Drill collar specifications: APISPEC7-1, APISPEC 7-2 and API RP7G
VIDEO
Drill Collar Number
Outside Diameter
Inside Diameter
Length
Bevel dia.
Ref.Bending strength Ratio
Df
mm
in
mm
in
mm
ft
in
NC23-31
79.4
3 1/8
31.8
1 1/4
9150
30
3
2.57:1
NC26-35(2 3/8IF)
88.9
3.5
38.1
1.5
9150
30
3 17/64
2.42 :
1
NC31-41(2 7/8IF)
104.8
4 1/8
50.8
2
9150&9450
30 or 31
3 61/64
2.43 :
1
NC35-47
120.7
4 3/4
50.8
2
9150&9450
30 or 31
4 33/64
2.58 :
1
NC38-50
127
5
57.2
2 1/4
9150&9450
30 or 31
4 49/64
2.38 :
1
NC44-60
152.4
6
57.2
2 1/4
9150&9450
30 or 31
5 11/16
2.49 :
1
NC44-60
152.4
6
71.4
2 13/16
9150&9450
30 or 31
5 11/16
2.84 :
1
NC44-62
158.8
6 1/4
57.2
2 1/4
9150&9450
30 or 31
5 7/8
2.91 :
1
NC46-62
158.8
6 1/4
71.4
2 13/16
9150&9450
30 or 31
5 29/32
3.63 :
1
NC46-65(4IF)
165.1
6.5
57.2
1 1/4
9150&9450
30 or 31
6 3/32
2.76 :
1
NC46-65(4IF)
165.1
6.5
71.4
2 13/16
9150&9450
30 or 31
6 3/32
3.05 :
1
NC-46-67(4IF)
171.4
6.75
57.2
.2 1/4
9150&9450
30 or 31
6 9/32
3.18 :
1
NC50-67
171.4
6.75
71.4
2 13/16
9150&9450
30 or 31
6 9/32
2.37 :
1
NC50-70
177.8
7
57.2
2 1/4
9150&9450
30 or 31
6 31/64
2.54 :
1
NC50-70(4 1/2 IF)
177.8
7
71.4
2 13/16
9150&9450
30 or 31
6 31/64
2.73 :
1
NC50-72
184.2
7 1/4
71.4
2 13/16
9150&9450
30 or 31
6 43/64
3.12 :
1
NC56-77
196.6
7 3/4
71.4
2 13/16
9150&9450
30 or 31
7 19/64
2.70:1
NC56-80
203.2
8
71.4
2 13/16
9150&9450
30 or 31
7 31/64
3.02 :
1
6 5/8 REG
209.6
8 1/4
71.4
2 13/16
9150&9450
30 or 31
7 45/64
2.93 :
1
NC61-90
228.6
9
71.4
2 13/16
9150&9450
30 or 31
8 3/8
3.17 :
1
7 5/8 REG
241.3
9 1/2
76.2
3
9150&9450
30 or 31
8 13/16
2.81 :
1
NC70-97
247.6
9 3/4
76.2
3
9150&9450
30 or 31
9 5/32
2.57 :
1
NC70-100
254
10
76.2
3
9150&9450
30 or 31
9 11/32
2.81 :
1
8 5/8 REG
279.4
11
76.2
3
9150&9450
30 or 31
10 1/2
2.84 :
1
Note:
1. Effective Length range:30ft or 31ft.
2. Joint tool thread cold working(C/W).
3.(SRG)stress relief groove and bore back box. Manufactured according to API 7-1 latest version.