The drill collar is located below the drill pipe and above the drill bit; drill collars can generally be divided into round drill collars, spiral drill collars and non-magnetic drill collars for downhole magnetic instruments.
The drill collar is located below the drill pipe and above the drill bit; drill collars can generally be divided into round drill collars, spiral drill collars and non-magnetic drill collars for downhole magnetic instruments.
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
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. |