Drill pipe is attached to the far side of the reamer so that it can be pulled back from the near side, once the pre-reaming operation is complete.

扩孔器远侧与钻杆相连，当预扩孔作业完成后，可以将扩孔器从近侧拖回到远侧。

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Drill pipe is attached to the far side of the reamer so that it can be pulled back from the near side, once the pre-reaming operation is complete.

扩孔器远侧与钻杆相连，当预扩孔作业完成后，可以将扩孔器从近侧拖回到远侧。

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