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: 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.

large outer pipe, often a form or a barrier.

n: a drilling platform that rests on a steel or concrete caisson. Used mainly in the Arctic, caissontype drilling platforms are mobile offshore drilling units built to withstand the ravages of moving ice in Arctic waters.

n: see caissontype drilling platform. platform rig.

n: a rigid offshore drilling platform built of steelreinforced concrete and used to drill development wens. The platform is floated to the drilling site in a vertical position. At the site, one or more tall caissons that serve as the foundation of the platform are flooded so that the platform 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.

caisson-retained island.

deep draft caisson vessel.

n: (MAC) a submersible offshore drilling rig designed to drill in the ice-choked waters of the arctic. It consists of a caisson base, which is a large concrete or steel tube. that rests on the seafloor. The drilling equipment is installed on top of the caisson above the water (ice) line. The caisson is built to withstand the enormous force of moving pack ice.