Drill Collars Parameter
Size OD | Bore | Connection | Weight (kg) | Bevel | |
(in/mm) | (in/mm) | Type | 30 feet | 31 feet | Diameter |
3 1/8 (79.4) | 1 1/4 (31.8) | NC23 | 296 | 306 | 76.2 |
3 1/2 (88.9) | 1 1/2 (38.1) | NC26 | 358 | 370 | 82.9 |
4 1/8 (104.8) | 2 (50.8) | NC31 | 469 | 485 | 100.4 |
4 3/4 (120.7) | 2 (50.8) | NC 35 | 629 | 650 | 114.7 |
5 (127) | 2 1/4 (57.2) | NC38 | 716 | 740 | 121 |
6 (152.4) | 2 1/4 (57.2) | NC44 | 1114 | 1151 | 144.5 |
6 (152.4) | 2 13/16 (71.4) | 4 1/2 FH | 1011 | 1045 | 144.5 |
6 1/4 (158.8) | 2 1/4 (57.2) | NC46 | 1224 | 1265 | 149.2 |
6 1/4 (158.8) | 2 13/16 (71.4) | NC46 | 1123 | 1160 | 150 |
6 1/2 (165.1) | 2 1/4 (57.2) | NC46 | 1340 | 1385 | 154.8 |
6 1/2 (165.1) | 2 13/16 (71.4) | NC50 | 1237 | 1278 | 154.8 |
6 3/4 (171.4) | 2 1/4 (57.2) | NC46 | 1024 | 1058 | 159.5 |
Connection Interchange List
NC (numbered Conn.) | 26 | 31 | 38 | 40 | 46 | 50 |
IF (internal flush) | 2 3/8 | 2 7/8 | 3 1/2 | 4 | 4 1/2 | |
FH (full hole) | 4 | |||||
SH (slim hole) | 2 7/8 | 3 1/2 | 4 1/2 | |||
XH (extra hole) | 4 1/2 | 5 |
API Mechanical Properties of Drill Collars
Outside Diameter | Outside Diameter | Tensile Strength | Yield Strength | Elongation (L=4D) | Impact AKV | Brinell Hardness |
Inch | mm | Mpa | Mpa | % | J | HB |
3 1/8-6 3/4 | 79.4-171.4 | ≥965 | ≥758 | ≥13 | ≥54 | ≥285 |
7-10 | 177.8-254 | ≥930 | ≥689 | ≥13 | ≥54 | ≥285 |
