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 [...]

A floating production, storage and offloading vessel (fpso; also called a “unit” and a “system”) is a type of floating tank system used by the offshore oil and gas industry and designed to take all of the oil or gas produced from nearby platforms or templates, process it, and store it until the oil or [...]

A drilling rig that is used exclusively to drill offshore exploration and development wells and that floats upon the surface of the water when being moved from one drill site to another. it may or may not float once drilling begins. two basic types of mobile offshore drilling units are used to drill most offshore [...]

A type of mobile offshore drilling unit that floats and is not secured to the seafloor (except for anchors). floating units include inland barge rigs, drill ships and ship-shaped barges, and semisubmersibles. see mobile offshore drilling unit.

A type of mobile offshore drilling unit that has a part of its structure in contact with the seafloor when it is on site and drilling a well. the remainder of the rig is supported above the water. the rig can float, however, allowing it to be moved from one drill site to another. bottom-supported [...]

Heavy crude oil or extra heavy crude oil is any type of crude oil which does not flow easily. it is referred to as “heavy” because its density or specific gravity is higher than that of light crude oil.
heavy crude oil has been defined as any liquid petroleum with an api gravity less than [...]

1. for ships, water taken onboard into specific tanks to permit proper angle of repose of the vessel in the water, and to assure structural stability. 2. for mobile offshore drilling rigs, weight added to make the rig more seaworthy, increase its draft, or sink it to the seafloor. seawater is usually used for ballast, [...]

Abbr. health, safety and environment.

The evaluation of physical properties, usually including pressure, temperature and wellbore trajectory in three-dimensional space, while extending a wellbore. mwd is now standard practice in offshore directional wells, where the tool cost is offset by rig time and wellbore stability considerations if other tools are used.
the measurements are made downhole, stored in solid-state memory [...]

A blowout preventer placed on the seafloor for use by a floating offshore drilling rig.

A retrievable tool used to suspend drilling temporarily during a storm offshore.

The representative of the oil company or operator on a drilling location. for land operations, the company man is responsible for operational issues on the location, including the safety and efficiency of the project. even administrative managers are expected to respond to the direction of the company man when they are on the rigsite. offshore, depending on [...]

1. any of various external electrical lines or fluid tubes which connects one portion of a system to another.
2. a control line attached to a remove piece of equipment, usually a subsea wellhead, to provide hydraulic or electrical control, or inject small amounts of chemicals.

A working shift for drilling crew or other oilfield workers. the most common tour is 8 hours; the three daily tours are called daylight, evening (or afternoon), and graveyard (or morning). sometimes 12-hour tours are used, especially on offshore rigs; they are called simply day tour and night tour.

The component in a blowout preventer that cuts, or shears, through drill pipe and forms a seal against well pressure. shear rams are used in floating offshore drilling operations to provide a quick method of moving the rig away from the hole when there is no time to trip the drill stem out of the [...]