دیکشنری تخصصی مهندسی نفت - نسخه آنلاین

n: a mobile submersible drilling structure used in arctic areas. The rig is towed onto the drilling site and submerged during periods when the water is free of ice. All equipment below the waterline is surrounded by a caisson to protect it from damage by moving ice. The drilling deck has no square comers so that moving ice can better flow around it. See submersible drilling rig.

n: a mobile submersible drilling structure constructed of several steel cylinders or bottles. When the bottles are flooded, the rig submerges and rests on bottom;when water is removed from the bottles, the rig floats. The latest designs of this type of rig drill in water depths up to 100 feet (30.5 metres). See submersible drilling rig.

n: the pressure exerted on the bottom hull of a columnstabilised semisubmersible drilling rig when the hull is submerged to drilling water depth.

n: the lower deck of a doubledecked semisubmersible drilling rig. See milin deck, Texas deck.

n: see semisubmersible drilling rig.

n: a walled round hole or well in the hull of a drill ship, ship-shape barge, or semisubmersible drilling rig (usually in the centre) through which the drilling assembly and other assemblies pass while a well is being drilled, completed, or abandoned.

an open shaft in a deep-sea drilling vessel, usually located in the center of the hull, through which the drilling takes place.

n: any of various types of drilling structures designed for use in drilling wells in oceans, seas, bays, gulfs, and so forth. Offshore rigs include platforms, jack up drilling rigs, semi-submersible drilling rigs, submersible drilling rigs, and drill ships. Compare land rig.

n: a mobile submersible drilling structure consisting of a barge hull that rests on bottom. steel posts that rise from the top of the barge hull. and a deck that is built on top of the posts. well above the waterline. It is used to drill wells in water no deeper than about 30 to 35 feet (9 to 10.7 metres). Most posted barge submersibles work in inland gulfs and bays. See submersible drilling rig.

n: see semisubmersible drilling rig.

n: a floating offshore drilling unit that has pontoons and columns that, when flooded. cause the unit to submerge to a predetermined depth. Living quarters, storage space, and so forth are assembled on the deck. Semisutxnersible rigs are self-propelled or towed to a drilling site and anchored or dynamically positioned over the site, or both. In shallow water, some semi-submersibles can be ballasted to rest on the seabed. Semi-submersibles ale more stable than drill ships and ship-shaped barges and are used extensively to drill wildcat wells in rough waters such as the North Sea. Two types of semi-submersible rigs ale the bottle- type and the column-stabilized. See floating offshore drilling rig.