دیکشنری تخصصی مهندسی نفت - نسخه آنلاین

n: one of several valves installed at the wellhead to prevent the escape of pressure either in the annular space between the casing and the drill pipe or in open hole (i.e., hole with no drill pipe) during drilling or completion operations. Blow- out preventers on land rigs are located beneath the rig at the lands surface;on jackup or platform rigs, at the waters surface;and on floating offshore rigs, on the seafloor. See annular blowout preventet;ram blowout preventer:

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: see caissontype drilling platform. platform rig.

n: an offshore platform that is designed to flex with wind and waves. Two types are the guyed-tower platform rig and the compliant piled tower.

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.

n: see platform rig.

n: a compliant offshore drilling platform used to drill development wells. The foundation of the platform is a relatively lightweight jacket on 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.

n: an immobile offshore structure from which development wells are drilled and produced. Platform rigs may be built of steel or concrete and may be rigid or compliant. Rigid platform rigs, which rest on the seafloor, are the caisson- type platform, the concrete gravity platform, and the steeljacket platform. Compliant platform rigs, which are used in deeper waters and yield to water and wind movements, are the guyedtower plat- form, the tension-leg platform, and the compliant piled tower platform.

n: see platform rig.

n: 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 (such as a platform rig). Sometimes, several satellite wells will be drilled to exploit marginal reservoirs and avoid the enormous expense of erecting a platform.