Drill String

A drill string, also called a drill stem or drill pipe, consists of 30-foot (9-m) lengths of steel tubing fitted together to form a long conduit that connects the drill bit to a drilling rig.^[1] The rotation of the drill string is what drills the hole. The drill string also acts as a conduit for drilling mud.

[edit] References

1. ↑ Learn how to talk like an Oilman. Maverick Energy Inc. 25-05-2009.