Kelly on an oil rig

Discussion in 'English Only' started by wordiana, Jan 28, 2008.

  1. wordiana Member

    Novi Sad
    Hi, everybody,
    I can't find it in a dictionary,
    I suppose it's a part of an oil rig,
    but what it actually is and what it actually does, I really don't know.
    They are drilling in search of oil and at the target depth, the owner of the drill site says:
    "I think we are through the zone, because it is, the kelly is bouncing real hard."
    I appreciate your help.
  2. Mister Micawber

    Mister Micawber Senior Member

    USA, English
    Kelly: The rod attached to the top of the drill column in rotary drilling. It passes through the rotary table and is turned by it, but is free to slide down through it as the borehole deepens. Also called grief stem. (

    Kelly: A long square or hexagonal steel bar with a hole drilled through the middle for a fluid path. The kelly is used to transmit rotary motion from the rotary table or kelly bushing to the drillstring, while allowing the drillstring to be lowered or raised during rotation. The kelly goes through the kelly bushing, which is driven by the rotary table. The kelly bushing has an inside profile matching the kelly's outside profile (either square or hexagonal), but with slightly larger dimensions so that the kelly can freely move up and down inside. (
  3. wordiana Member

    Novi Sad
    Thank you ever so much for your swift reply, and even more so for the links!
    If I only knew how do they call it in my language:) !
    Thanks, once again!

Share This Page