Rig Dictionary

 Two large support legs that when standing they form a steel A-frame structure that supports the derrick when it is     standing. They are also the support frames for the drilling line when raising or lowering the derrick.

 A storage device that delivers hydraulic fluid under pressure from nitrogen to operate the blowout preventers.

Used in surface mud systems to suspend solids and maintain homogeneous
mixture throughout the system. A mechanical agitator is driven by an explosion-proof motor, coupled to a gear box that drives the impeller shaft. The impellers (turbines) transform mechanical power into fluid circulation or agitation. The objective is to obtain a uniform suspension of all solids.

Air Compressor:
A machine that takes air, compresses it, and stores it in a tank so it can be distributed around the rig to various air driven equipment such as clutches and tuggers.

Air Hoist:
A compressed air powered winch-like device, usually mounted on the rig floor, used to lift heavy objects or tubulars to the rig floor. It is also called a “tugger” or a “winch”.

Annular Blowout Preventer:
A well control device, usually installed above the ram preventers, that is used to seal the annulus space between any shape of tubular and the well bore or, if no tubular is present, it will seal on an open wellbore.

The open downhole space between a tubular and the well bore wall. Also called the “annular space”.

Unexpected reverse motion of the tongs, left on a pipe or collar, during the pipe spinning operation.

Bale Eyes:
The end of the bale bars that form an enclosed eye.

Long, heavy steel bars with an eye on each end. One end attaches to the ears of the travelling blocks and the other end attaches to the ears of the elevators.

Weighting material used to increase the density of a liquid drilling fluid system.