AJ型安全接头是一种由两件组装起来的专用接头，是钻井、修井、试油(气)等工程中对钻柱起保护作用的一种专用工具。
AJ type safety joint is a specialized joint consisting of two parts. The specialized joint takes protective effect for drilling stem in drilling, repairing and test oil (gas) engineering, etc.
在石油工程修井过程中，修井机是非常重要的作业机械。
Workover machine rig is very important equipment in workover process of petroleum engineering.
在石油工程修井过程中，修井机是非常重要的作业机械。
Workover machine rig is very important equipment in workover process of petroleum engineering.
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