دیکشنری تخصصی مهندسی نفت - نسخه آنلاین

n: see lower kelly cock.

a full opening valve with threads that match the drill pipe that can be quickly screwed onto the pipe to help control fluid flow up the tubing.

n: a special valve normally installed below the kelly. Usually, the valve is open so that drilling fluid can flow out of the kelly and down the drill stem. It can, however, be manually closed with a special wrench when necessary. In one case, the valve is closed and broken out, still attached to the kelly to prevent drilling mud in the kelly from draining onto the rig floor. In another case, when kick pressure inside the drill stem exists, the drill stem safety valve is closed to prevent the pressure from escaping up the drill stem. Also called lower kelly cock, mud saver valve.

n: a valve installed at one or both ends of the kelly. When a high-pressure backflow occurs inside the drill stem, the valve is closed to keep pressure off the swivel and rotary hose. See lower kelly cock, upper kelly cock.

n: a valve installed between the kelly and the swivel,it is used to control a backflow of fluid up the drill string and isolate the swivel and hose from high pressure.

the valve on the Kelly.

n: a special valve normally installed below the kelly. Usually, the valve is open so that drilling fluid can flow out of the kelly and down the drill stem. When the mud pump is stopped, the valve can be manually closed with a special wrench to prevent pressurised fluids in the drill string from flowing into the kelly. When closed, the valve also prevents mud in the kelly from spilling onto the rig floor when the kelly is broken out of the drill string. Also called a drill stem safety valve, mud saver valve.

n: see drill stem safety valve. lower kelly cock.

a near full-opening valve installed just below the kelly. It has the same outside diameter as the tool joints.

n: a lower kelly cock. See drill stem safety valve, lower kelly cock.