Oil & Gas Glossary 1.0

A portable mast constructed of tubular members. A pole mast may be a single pole, usually one or two different sizes of pipe telescoped together to be moved or extended and locked to obtain maximum height above a well. Double-pole masts give added strength and stability. See mast.

A mast on a well servicing unit that utilizes a split traveling block and crown block, which makes it possible to pull 60-foot stands with a 50-foot mast.

A mast mounted on a truck and capable of being erected as a single unit. See telescoping derrick.

A well-servicing unit whose mast consists of two steel tubes. Double-pole masts provide racking platforms for handling rods and tubing in stands and extend from 65 to 67 feet (20 meters) so that rods can be suspended as 50-foot (15 meter) doubles and tubing set back as 30-foot (9-meter) singles. See pole mast.

A projecting member run out at an angle from the sides of a portable mast or a land crane to the ground to provide stability and to minimize the possibility of having the mast or the crane overturn.

A portable derrick that is capable of being erected as a unit, as distinguished from a standard derrick that cannot be raised to a working position as a unit. For transporting by land, the mast can be divided into two or more sections to avoid excessive length extending from truck beds on the highway. Compare derrick.

A small platform with finger-like steel projections attached to the side of the mast on a well servicing unit. When a string of sucker rods or tubing is pulled from a well, the top end of the rods or tubing is placed (racked) between the steel projections and held in a vertical position in the mast.

A rope or cable used to steady a mast or pole.

A device used to hang sucker rods on the mast or in the derrick

The foundation on which the derrick or mast and usually the drawworks sit. It contains space for storage and well-control equipment.

The derrick or mast, drawworks, and attendant surface equipment of a drilling or workover unit.

A well-servicing unit whose mast consists of but one steel tube, usually about 65 feet long.

A piece of wood or concrete, usually buried, to which a wire guy line is attached for bracing a mast or tower.

The wireline attached to ground anchors to provide lateral support for a mast or derrick.

A vertical pipe rising along the side of the derrick or mast, which joins the discharge line leading from the mud pump to the rotary hose and through which mud is pumped going into the hole.

To suspend sucker rods in a derrick or mast on rod hangers rather than horizontally on a rack.

A wireline attached to a mast, derrick, or offshore platform to stabilize it. See wind guy line.

An arrangement of pulleys, or sheaves, through which drilling line is reeved and which moves up and down in the derrick or mast. See block.

A portable servicing or workover rig that is self-propelled, using the hoisting engines for motive power. Because the driver's cab is mounted on the end opposite the mast support, the unit must be backed up to the wellhead. See carrier rig.

To place stands of drill pipe and drill collars in a vertical position to one side of the rotary table in the derrick or mast of a drilling or workover rig. Compare lay down pipe.

The connected joints of pipe racked in the derrick or mast during a trip. The usual stand is about 90 feet long (about 27 meters), which is three lengths of drill pipe screwed together (a thribble).

A type of portable service or workover rig that is self-propelled, using power from the hoisting engines. The driver's cab and steering wheel are mounted on the same end as the mast support; thus the unit can be driven straight ahead to reach the wellhead. See carrier rig.

An opening at floor level in a side of a derrick or mast. The V-door is opposite the drawworks and is used as an entry to bring in drill pipe, casing, and other tools from the pipe rack. The name comes from the fact that on the old standard derrick, the shape of the opening was an inverted V.

The derrickman's working platform. As pipe of tubing is run into or out of the hole, the derrickman must handle the top end of the pipe, which may be as high as 90 feet (27 m) in the derrick or mast. The monkeyboard provide a small platform to raise him to the proper height for handling the top of the pipe.

A portable servicing or workover outfit, usually mounted on wheels and self-propelled. A well servicing unit consists of a hoist and engine mounted on a wheeled chassis with a self-erecting mast. A workover rig is basically the same, with the addition of a substructure with rotary, pump, pits, and auxiliaries to permit handling and working a drill string.

A portable mast that an be erected as a unit, usually by a tackle that hoists the wireline or by hydraulic pistons. The upper section of a telescoping derrick is generally nested (telescoped) inside the lower section of the structure and raised to full height either by the wireline or by a hydraulic system.

A large load-bearing structure, usually of bolted construction. In drilling, the standard derrick has four legs standing at the corners of the substructure and reaching to the crown block. The substructure is an assembly of heavy beams used to elevate the derrick and provide space to install blowout preventers, casingheads, and so forth. Because the standard derrick must be assembled piece by piece, it has largely been replaced by the mast, which can be lowered and raised without disassembly.