Annular Blowout Preventer A large valve, usually installed above the ram preventers, that forms a seal in the annular space between the pipe and well bore. If no pipe is present, it forms a seal on the well bore itself.
Annulus The space around a pipe in a well bore,the outer wall of which may be the wall of either the bore hole or the casing; sometimes termed the annular space.
Blowout Preventer A large valve, usually installed above the ram preventers, that forms a seal in the annular space between the pipe and well bore or, if no pipe is present, on the well bore itself.
Brake The braking device on the drawworks to stop a load being lifted.
BulkMud Components in Storage Hopper type tanks for storage of drilling fluid components.
Casing Head A heavy, flanged steel fitting connected to the first string of casing. It provides a housing for slips and packing assemblies, allows suspension of intermediate and production strings of casing, and supplies the means for the annulus to be sealed off. Also called a spool.
Cathead A spool-shapedattachment on a winch around which rope for hoisting and pulling is wound.
Catline Boom and Hoist Line A structural framework erected near the top of the derrick for lifting material.
Catwalk The ramp at the side of the drilling rig where pipe is laid to be lifted to the derrick floor by the catline or by an air hoist.
Cellar A pit in the ground to provide additional height between therig floor and the well head to accommodate the installation of blowout preventers, ratholes, mouseholes, and so forth. It also collects drainage water and other fluids for disposal.
Choke Manifold The arrangement of piping and special valves, called chokes, through which drilling mud is circulated when the blowout preventers are closed to control the pressures encountered during a kick.Conductor Pipe The largest diameter casing and the topmost length of casing. It is relatively short and encases the topmost string of casing.
Crown Block and Water Table An assembly of sheaves or pulleys mounted on beams at the top of the derrick. The drilling line is run over the sheaves down to the hoisting drum.
Degasser The equipment used to remove unwanted gas from a liquid, especiallyfrom drilling fluid.
Desander A centrifugal device for removing sand from drilling fluid to prevent abrasion of the pumps. It may be operated mechanically or by a fast moving stream of fluid inside a special coneshaped vessel, in which case it is sometimes called a hydrocyclone.
Desilter A centrifugal device, similar to a desander, used to remove very fine particles, or silt, from drillingfluid. This keeps the amount of solids in the fluid to the lowest possible level.
Doghouse A small enclosure on the rig floor used as an office for thedriller or as a storehouse for small objects. Also, any small building used as an office or for storage.
Drill Bit The cutting or boring element used in drilling oil and gas wells. Most bits used in rotary drilling are roller-cone bits. The bitconsists of the cutting elements and the circulating element. The circulating element permits the passage of drilling fluid and uses the hydraulic force of the fluid stream to improve drilling rates.
Drawworks The hoisting mechanism on a drilling rig. It is essentially a large winch that spools off or takes in the drilling line and thus raises or lowers the drill stem and bit.
Drill Collar Aheavy, thick-walled tube, usually steel, used between the drill pipe and the bit in the drill stem. It is used to put weight on the bit so that the bit can drill.
Drill Pipe The heavy seamless tubing used to rotate the bit and circulate the drilling fluid. Joints of pipe 30 feet long are coupled together with tool joints.
Driller's Console The control panel, located on the platform, where...