Oil & Gas Glossary 1.0

A special device that, when fitted in to the master bushing, transmits torque to the kelly and simultaneously permits vertical movement of the kelly to make hole. It may be shaped to fit the rotary opening or have pins for transmitting torque. Also called

A valve installed above the kelly that can be closed manually to protect the rotary hose from high pressure that may exist in the drill stem

Those parts of the drilling or workover rig that are designed to turn or rotate the drill stem and bit - swivel, kelly, kelly busing, master bushing, and rotary table.

A short, threaded piece of pipe used to adapt parts of the drilling string that cannot otherwise be screwed together because of differences in thread size or design. A sub (i.e., a substitute) may also perform a special function. Lifting subs are used with drill collars to provide a shoulder to fit the drill pipe elevators; a kelly saver sub is placed between the drill pipe and the kelly to prevent excessive thread wear of the kelly and drill pipe threads, a bent sub is used when drilling a directional hole.

A special valve 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 close to prevent the pressure from escaping up the drill stem.

An essentially full-opening valve installed immediately below the kelly, with outside diameter equal to the tool joint outside diameter.

An essentially full-opening valve installed immediately below the kelly, with outside diameter equal to the tool joint outside diameter.

A reinforced flexible tub on a rotary drilling rig that conducts the drilling fluid from the standpipe to the swivel and kelly. Also called the mud hose or the kelly hose

A device that fits into the rotary table to accommodate the slips and drive the kelly bushing so that the rotating motion of the rotary table to accommodate the slips and drive the kelly bushing so that the rotating motion of the rotary table can be transmitted to the kelly. Also called rotary bushing.

The machine used to impart rotational power to the drill stem while permitting vertical movement of the pipe for rotary drilling. Modern rotary machines have a special component, the rotary or master bushing, to turn the kelly bushing, which permits vertical movement of the kelly while the stem is turning.

See lost circulation. lower kelly cock n: see drill stem safety valve

See lost circulation. lower kelly cock n: see drill stem safety valve

1. a hole in the rig floor, 30 to 35 feet (9 to 11 meters) deep, which is lined with casing that projects above the floor and into which the kelly and swivel are placed when hoisting operations are in progress.

See kelly bushing

All members in the assembly used for rotary drilling from the swivel to the bit, including the kelly, drill pipe and tool joints, drill collars, stabilizers, and various specialty items. Compare drill string.

All members in the assembly used for rotary cutting from the swivel to the ball, including the kelly, drill pipe and tool joints, drill collars, stabilizers, and various specialty items. Compare drill string.

The heavy steel member, three-, four-, six-, or eight-sided, suspended from the swivel through the rotary table and connected to the topmost joint of drill pipe to turn the drill stem as the rotary table turns. It has a bored passageway that permits fluid

The column, or string, of drill pipe with attached tool joints that transmits fluid and rotational power from the kelly to the drill collars and bit. Often, especially in the oil patch, the term is loosely applied to both drill pipe and drill collars. Compare drill stem.

The column, or string, of drill pipe with attached tool joints that transmits fluid and rotational power form the kelly to the drill collars and bit. Often, especially in the oil patch, the term is loosely applied to both drill pipe and drill collars. Compare drill stem.

A sealing device used to close off the annular space around the kelly in drilling with pressure at the surface, usually installed above the main blowout preventers. A rotating head makes it possible to drill ahead even when there is pressure in the annulus that the weight of the drilling fluid is not overcoming; the head prevents the well from blowing out. It is used mainly in the drilling of formations that have low permeability. The rate of penetration through such formations is usually rapid.

Also called kelly hose or rotary hose. See rotary hose.

Seamless steel or aluminum pipe made up in the drill stem between the kelly or top drive on the surface and the drill collars on the bottom. During drilling, it is usually rotated while drilling fluid is circulated through it. Drill pipe joints are available in three ranges of length: 18 to 22 feet, 27 to 30 feet, and 38 to 45 feet. The most popular length is 27 to 30 feet. It is available with outside diameters ranging from 2 7/8 to 5 1/2 inches. Several joints are made up (screwed together) to form the drill string.