دیکشنری تخصصی مهندسی نفت - نسخه آنلاین

n: a floating marker used in a spread mooring system to position each anchor of a semi-submersible rig or drill ship. See spread mooring system.

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: a type of mobile offshore drilling unit (MODU) 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 units include submersible rigs and jack up rigs. See mobile offshore drilling unit.

n: 1. one of several columns made of steel or concrete that serve as the foundation for a rigid offshore platform rig, such as the concrete gravity platform rig. 2.equipment below the waterline of an Arctic submersible rig, thereby protecting the equipment from damage by moving ice.

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: 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.

n: a mobile bottom supported offshore drilling structure with several compartments that are flooded to cause the structure to submerge and rest on the seafloor. Submersible rigs are designed for use in shallow waters to a maximum of 175 feet (53.4 metres). Submersible drilling rigs include the posted barge submersible, the bottle-type submersible, and the arctic submersible. See bottom-supported offshore drilling rig.

a large rig supported and stabilized by underwater pontoons.