A drill string on a drilling rig is a column, or string, of drill pipe that transmits drilling fluid (via the mud pumps) and torque (via the kelly drive or top drive) to the drill bit. The term is loosely applied as the assembled collection of the drill pipe, drill collars, tools and drill bit. The drill string is hollow so that drilling fluid can be pumped down through it and circulated back up the annulus (the void between the drill string and the casing/open hole).
Read more about Drill String: Drill String Components, Running A Drill String, Stuck Drill String
Famous quotes containing the words drill and/or string:
“Swift blazing flag of the regiment,
Eagle with crest of red and gold,
These men were born to drill and die.
Point for them the virtue of slaughter,
Make plain to them the excellence of killing
And a field where a thousand corpses lie.”
—Stephen Crane (1871–1900)
“First you find a little thread, a little thread leads you to a string, and the string leads you to a rope. And from the rope you hang by the ... neck.”
—A.I. (Albert Isaac)