drill collar

基本解釋

While installing or removing the drill collar clamp, hold weight of string with block.
任何時(shí)候都不能擋住司鉆看井口鉆桿的視線。
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Main reasons of causing drill collar screw failure are discovered by way of further investigation and analysis on these problems.
通過(guò)對(duì)鉆鋌螺紋失效問(wèn)題的深入調(diào)查和分析，找出引起鉆鋌螺紋失效的主要原因。
Do not make up or break out the bit on a single joint of DC. If this is absolutely necessary, always snub drill collar with the air tugger.
不要在一單根鉆鋌上卸鉆頭，如果確實(shí)需要這樣做，要用氣動(dòng)絞車?yán)°@鋌。
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