Drill Collar
There are different kinds of drill collars,including round drill collar,spiral drill collar,non-magnetic drill collar,square drill collar and so on.Ordinary drill collar is the circular cross section, the center has a water hole,the wall thickness is larger,the nozzle is smaller, the weight of per unit length is greater than the size of drill pipe almost 4- 5 times .The majority of drill collar is thread processing directly on the pipe body , but some of them also use the replaced joint.
Features
(1)Eccentric-weight drill collar is an effective anti-deviation drilling tool,with high drill pressure used in oblique areas,rectifying oblique as well.
(2)When drilling directional wells eccentric-weight drill collar is an effective tool to reduce oblique or straighten the well hole using high drilling pressure.
(3)Eccentric-weight drill collar has the advantages of simple structure,convenient use,connected directly to common drill collar without centralizers,greatly convenient for sinking in,fishing and milling operations.
(4)Eccentric-weight drill collar runs downhole safely,danger of leakage or bit freezing hard to appear.
(5)Pay much attention to avoid mud balling and prevent effect of anti-deviation .
| Drill Collar Specification | ||||||||
| Thread Type | O.D. | I.D. | Length | Diameter of shoulder guide Angle | Reference bending strength ratio | |||
| mm | inch | mm | inch | mm | inch | |||
| NC23-31 | 79.4 | 31/8 | 31.8 | 11/4 | 9150 | 30ft | 76.2 | 2.57:1 |
| NC26-35(23/8IF) | 88.9 | 31/2 | 38.1 | 11/2 | 82.9 | 2.42:1 | ||
| NC31-41(27/8IF) | 104.8 | 41/8 | 50.8 | 2 | 100.4 | 2.43:1 | ||
| NC35-47 | 120.7 | 43/4 | 50.8 | 2 | 114.7 | 2.58:1 | ||
| NC38-50(31/2IF) | 127 | 5 | 57.2 | 21/4 | 121 | 2.38:1 | ||
| NC44-60 | 152.4 | 6 | 57.2 | 21/4 | 9150or9450 | 30ftor31ft | 144.5 | 2.49:1 |
| NC44-60 | 152.4 | 6 | 71.4 | 213/16 | 144.5 | 2.84:1 | ||
| NC44-62 | 158.8 | 61/4 | 57.2 | 21/4 | 149.2 | 2.91:1 | ||
| NC46-62(4IF) | 158.8 | 61/4 | 71.4 | 213/16 | 150 | 2.63:1 | ||
| NC46-65(4IF) | 165.1 | 61/2 | 57.2 | 21/4 | 154.8 | 2.76:1 | ||
| NC46-65(4IF) | 165.1 | 61/2 | 71.4 | 213/16 | 154.8 | 3.05:1 | ||
| NC46-67(4IF) | 171.4 | 63/4 | 57.2 | 21/4 | 159.5 | 3.18:1 | ||
| NC50-67(41/2IF) | 171.4 | 63/4 | 71.4 | 213/16 | 159.5 | 2.37:1 | ||
| NC50-70(41/2IF) | 177.8 | 7 | 57.2 | 21/4 | 164.7 | 2.54:1 | ||
| NC50-70(41/2IF) | 177.8 | 7 | 71.4 | 213/16 | 164.7 | 2.37:1 | ||
| NC50-72(41/2IF) | 184.2 | 71/4 | 71.4 | 213/16 | 169.5 | 3.12:1 | ||
| NC56-77 | 196.8 | 73/4 | 71.4 | 213/16 | 185.3 | 2.70:1 | ||
| NC56-80 | 203.2 | 8 | 71.4 | 213/16 | 190.1 | 3.02:1 | ||
| 65/8REG | 209.6 | 81/4 | 71.4 | 213/16 | 195.7 | 2.93:1 | ||
| NC61-90 | 228.6 | 9 | 71.4 | 213/16 | 212.7 | 3.17:1 | ||
| 75/8REG | 241.3 | 91/2 | 76.2 | 3 | 223.8 | 2.81:1 | ||
| NC70-97 | 247.6 | 93/4 | 76.2 | 3 | 232.6 | 2.57:1 | ||
| NC70-100 | 254 | 10 | 76.2 | 3 | 237.3 | 2.81:1 | ||
| 85/8REG | 279.4 | 11 | 76.2 | 3 | 266.7 | 2.84:1 | ||
| Note: 1.Drill collar thread type: NC-Digital IF-Internal flat type REG-Normal type | ||||||||
| 2.Bending strength ratio: the ratio of the modulus of the cross section and the modulus of the cross section of the cross section of the dangerous section of the inner thread | ||||||||
| In addition, our company can produce the drill collar and spiral drill collar, which can also produce the special specifications of the drill collar and the high efficiency and wear-resisting lengthening drill collar | ||||||||
| O.D. | cutting depth | Lead ±25.4 | ||
| mm | in | A(mm) | B(mm) | mm |
| 86 | 3.375 | 3.5±0.79 | 679 | |
| 98.4 | 3.875 | 4.0±0.79 | 914 | |
| 101.6～111.1 | 4～4 1/8 | 4.8±0.79 | 914 | |
| 114.3～130.2 | 4 1/2～5 1/8 | 5.6±0.79 | 965 | |
| 133.4～146.1 | 5 1/4～5 3/4 | 6.4±0.79 | 1067 | |
| 149.2～161.9 | 5 7/8～6 3/8 | 7.1±1.59 | 1067 | |
| 165.1～177.8 | 6 1/2～7 | 7.9±1.59 | 1168 | |
| 181.0～200.0 | 7 1/8～7 7/8 | 8.7±1.59 | 5.6±0.79 | 1626 |
| 203.2～225.4 | 8～8 7/8 | 9.5±1.59 | 6.4±0.79 | 1727 |
| 228.6～250.8 | 9～9 7/8 | 10.3±2.37 | 7.1±1.59 | 1829 |
| 254.0～276.2 | 10～10 7/8 | 11.1±2.37 | 7.9±1.59 | 1930 |
| 279.4 | 11 | 11.9±2.37 | 8.7±1.59 | 2032 |
Advantages of Drill Collar Production Process:
In the process of heat treatment, the drill collar has added a special normalizing process, which makes the thread part grain more refined, enhances the drill collar thread strength, and effectively improves the service life of the drill collar.
| Sreel Mark | Chemical Composition % | ||||||||
| C | Si | Mn | P | S | Cr | Mo | Cu | Al | |
| 4145H | 0.42～0.48 | 0.15～0.35 | 0.90～1.20 | ≤0.03 | ≤0.03 | 0.90～1.20 | 0.15～0.25 | ≤0.2 | 0.025～0.045 |
| Other Elements：N≤0.015，Ni≤0.5 | |||||||||
| Drill Collar Mechanical Performance | ||||||||
| Drill Collar Outside Diameter Range | Yield Strength | Tensile Strength | Elongation A% | HB | Charpy Impact Akv J | |||
| mm | in | MPa | Psi | MPa | Psi | |||
| 79.4～171.4 | 3-1/8～6-3/4 | ≥758 | ≥110000 | ≥965 | ≥140000 | ≥13 | 285～341 | ≥54 |
| 177.8～279.4 | 7～11 | ≥689 | ≥100000 | ≥930 | ≥135000 | ≥13 | 285～341 | ≥54 |
| Under special conditions, the impact work of the charpy can be determined as greater than 70J according to the supply and demand | ||||||||
| Size | O.D（mm） | I.D.（mm） | Code | Thread | Length（mm） | Weight（kg） |
| 3-1/8 | 79.4 | 31.8（1-1/4） | NC23-31 | NC23 | 9140 | 298 |
| 3-1/2 | 88.9 | 38.1（1-1/2） | NC26-35 | NC26 | 9140 | 364 |
| 4-1/8 | 104.8 | 50.8（2） | NC31-41 | NC31 | 9140/9450 | 474/490 |
| 4-3/4 | 120.6 | 50.8（2） | NC35-47 | NC35 | 9140/9450 | 674/697 |
| 5 | 127.0 | 57.2（2-1/4） | NC38-50 | NC38 | 9140/9450 | 725/749 |
| 6 | 152.4 | 57.2（2-1/4） | NC44-60 | NC44 | 9140/9450 | 1125/1163 |
| 71.4（2-13/16） | NC44-60 | 9140/9450 | 1022/1056 | |||
| 6-1/4 | 158.8 | 57.2（2-1/4） | NC44-62 | NC44 | 9140/9450 | 1237/1279 |
| 71.4（2-13/16） | NC46-62 | 9140/9450 | 1134/1172 | |||
| 6-1/2 | 165.1 | 57.2（2-1/4） | NC46-65 | NC46 | 9140/9450 | 1352/1398 |
| 71.4（2-13/16） | NC46-65 | NC50 | 9140/9450 | 1249/1291 | ||
| 6-3/4 | 171.4 | 57.2（2-1/4） | NC46-67 | NC46 | 9140/9450 | 1471/1521 |
| 7 | 177.8 | 57.2（2-1/4） | NC50-70 | NC50 | 9140/9450 | 1597/1651 |
| 71.4（2-13/16） | NC50-70 | 9140/9450 | 1494/1545 | |||
| 7-1/4 | 184.2 | 71.4（2-13/16） | NC50-72 | NC50 | 9140/9450 | 1625/1680 |
| 7-3/4 | 196.8 | 71.4（2-13/16） | NC56-77 | NC56 | 9140/9450 | 1895/1960 |
| 8 | 203.2 | 71.4（2-13/16） | NC56-80 | NC56/6-5/8REG | 9140/9450 | 2040/2109 |
| 8-1/4 | 209.6 | 71.4（2-13/16） | 6-5/8REG | 6-5/8REG | 9140/9450 | 2188/2263 |
| 9 | 228.6 | 71.4（2-13/16） | NC61-90 | NC61 | 9140/9450 | 2658/2748 |
| 9-1/2 | 241.3 | 76.2（2-13/16） | 7-5/8REG | 7-5/8REG | 9140/9450 | 2954/3054 |
| 9-3/4 | 247.6 | 76.2（3） | NC70-97 | NC70 | 9140/9450 | 3127/3234 |
| 10 | 254.0 | 76.2（3） | NC70-100 | NC70 | 9140/9450 | 3308/3421 |
| 11 | 279.4 | 76.2（3） | 8-5/8REG | 8-5/8REG | 9140/9450 | 4072/4210 |
| Mechanical properties：＜7 inch Drill Collar：Yield Strength≥758MPa，Tensile Strength≥965MPa，Four times elongation≥13%，Impact energy Ak≥54J,（Single impact work≥47J，Average≥54J）Hardness range 285HB～341HB≥7inch Drill Collar：Yield Strength度≥689MPa，Tensile Strength≥931MPa，Four times elongation≥13%，Impact energy Ak≥54J,（Single impact work≥47J，Average≥54J） Hardness range 285HB～341HB | ||||||
