| 出生地 |
Zhejiang China (Mainland) |
| 牌子的名字 |
chenlong |
| 模式的数量 |
NC46-65(4IF) |
| 类型 |
钻头领 |
| 机器型号 |
钻探工具 |
| 验证 |
研究所 |
| 材料 |
高锰铁 |
| 使用 |
钻井 |
Drill collar is mainly used to provide bit weight to drill bit so that drill pipe is in tension.Especially drill collar can keep drill bit centralized and hole track by large rigidity.Drill collar are manufactured strictly by the standard API Spec7-1 and SY/T5411.