The string of tools that are used to drill a well, i.e., the kelly, drillpipe, drill collars, stabilizers and drilling bit.
Also called drill pipe or drill stem. Thirty-foot lengths of steel tubing screwed together to form a pipe connecting the drill bit to the drilling rig. The sting is rotated to drill the hole and also serves as a conduit for drilling mud.
Steel pipes roughly 10m long joined together to form a pipe from the drill bit to the drilling platform. It is rotated during drilling and is also the conduit for the drilling mud.