drill string的用法和樣例：
例句
- The calculation results demonstrate the effective eccentricity and the lifting force of the upper drill string are the major influential factors.
計算結果表明，有效偏心距和上部鉆柱的提升力是影響近井口套管偏磨的主要因素。 - A transmitter toroid induces a low-frequency current in the drillstring, which flows out of the bit and returns farther up the string.
發射線圈在鉆柱內感應出低頻電流，從鉆頭流出，在鉆柱上部返回。
