Once the drilling is complete, the shape of the round holes are modified by a millingoperation which increases the valved area.
一旦钻探完成，该圆孔形状修改碎行动瓣面积增加。
2
This design helps ensure that the mill follows the desired path and does not damage the casing or liner wall as the millingoperation progresses.
这种设计有助于确保铣刀沿着所要求的路径并在磨铣作业进行时不会损坏套管壁或衬管壁。
3
The rotary guide and the transport wheel with the variable speed, give to this machine the possibility to obtain a good millingoperation, safe and without specialized workers.