دیکشنری تخصصی مهندسی نفت - نسخه آنلاین

large, flat ocean floor, usually near a continent and usually over 4km (13100 ft) ss.

n: a system consisting of a beacon positioned on the seafloor to transmit an acoustic signal, a set of three or four hydrophones mounted on the hull of a floating offshore drilling vessel to receive the signal, and a position display unit to track the relative positions of the rig and the drill site. Monitoring of the display unit aids in accurate positioning of the rig over the site.

n: a hoist operated by compressed air;a pneumatic hoist. Air hoists are often mounted on the rig floor and are used to lift joints of pipe and other heavy objects.

n: US organisation that sets standards and specifications for ships and ship equipment manufactured in the United States. The organisation also makes inspections during offshore rig construction and conducts periodic surveys to ensure that requirements for classification are maintained. Its official publications are Records of the American Bureau of Shipping and ABS Activity Report. Address: 2 World Trade Centre;106th floor;New York, NY 10048;(212) 839- 5000.

n: serves as clearinghouse for nationally coordinated voluntary standards for fields ranging from information technology to building construction. Address: 11 W. 42nd Street, 13th floor;New York, NY 10036;(212) 642-4900.

n: The vertical heigh from the top of girder of drill floor to the bottom surface of crownblock beam.

n: The vertical heigh from the drill floor to the floor of monkey board.

the study and mapping of ocean floor topography.

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: controls, usually located near the drillers position on the rig floor, that are manipulated to open and close the blowout preventers. See blowout preventer.