Oil & Gas Glossary 1.0

An immobile offshore structure from which development wells are drilled and produced. Platform rigs may be built of steel or concrete and may be either rigid or compliant. Rigid platform rigs, which rest on the seafloor, are the caisson-type platform, the concrete gravity platform, and the steel-jacket platform. Compliant platform rigs, which are used in deeper waters and yield to water and wind movements are the guyed-tower platform and the tension-leg platform.

A rigid offshore drilling platform built of steel-reinforced concrete and used to drill development wells. The platform is floated to the drilling site in a vertical position, and at the site tall caissons that serve as the foundation of the platform are flooded so that the platform submerges and comes to rest on bottom. Because of the enormous weight of the platform, the force of gravity alone keeps it in place. See platform rig.

A compliant offshore drilling platform used to drill development wells. The foundation of the platform is a relatively lightweight jacket upon which all equipment is placed. A system of guy wires anchored by clump weights helps secure the jacket to the seafloor and allows it to move with wind and wave forces. See platform rig.

A rigid offshore drilling platform that stands on steel caissons and is used to drill development wells. The caissons are firmly affixed to the seafloor, and the drilling and production decks are laid on top of them. The platform is used in certain arctic waters, where the caissons are needed to protect equipment from moving ice. See platform rig.

1. one of several columns made of steel or concrete, which serves as the foundation for a rigid offshore platform rig, such as the concrete gravity platform rig.

See platform rig.

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.

Workover equipment designed in equipment packages or modules that are light enough to be lifted onto an offshore platform by a platform crane. In most cases, the maximum weight of a module of 12,000 pounds. Once lifted from the work boat, the rig can be erected and working within twenty-four to thirty-six hours.

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.

Usually a single well drilled offshore by a mobile offshore drilling unit to produce hydrocarbons from the outer fringes of a reservoir that cannot be produced by primary development wells drilled from a permanent drilling structure (as a platform rig). Sometimes, several satellite wells will be drilled to exploit marginal reservoirs and avoid the enormous expense of erecting a platform.

See platform rig.

A low platform mounted on the bottom of equipment for ease of moving, hauling, or storing.

All the devices used to accomplish the moving of sucker rods form the elevators to the racking platform.

Abbreviation: emergency shut down, an automated platform system to shut in an SCSSV and/or SSV

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

A special type of elevator designed to accommodate the end of a sucker rod. it allows the derrickman to transfer the rod to the racking platform from the regular elevator being used to lift the rod out of the well.

One of several valves installed at the wellhead to prevent the escape of pressure either in the annular space between the casing and drill pipe or in open hole (i.e., hole with no drill pipe) during drilling completion operations. Blowout preventers on land rigs are located beneath the rig at the land's surface; on jackup or platform rigs, at the water's surface; and on floating offshore rigs, on the seafloor.

Drilling for oil or gas in an ocean, gulf, or sea, usually on the Outer Continental Shelf. A drilling unit for offshore operations may be a mobile floating vessel with a ship or barge hull, a semisubmersible or submersible base, a self-propelled or towed structure with jacking legs (jackup drilling rig), or a permanent structure used as a production platform when drilling is completed. In general, wildcat wells are drilled from mobile floating vessels or from jackups, while development wells are drilled from platforms or jackups.