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U.S. Department of Energy
Office of Scientific and Technical Information

Unique concrete column offloads marine crude

Journal Article · · Pet. Eng. Int.; (United States)
OSTI ID:6111470

This paper describes the world's first buoyant articulated loading column (ALC) made principally of concrete and which can operate in the weather conditions of the North Sea. The ALC is an unmanned structure, mooring and loading being controlled by a tanker. Gravity base buoyancy tanks ''floaters'' are lightly reinforced and have a similar section to the column, 29.5 ft diameter and a wall thickness of 13.8 in. Before towing to the field, the column was ballasted by 1,000 metric tons of hematite, a fine ore aggregate. Final ballast will comprise 1,000 metric tons of hematite and 460 metric tons of water. Setting will be carried out by pumping water into the column until the base structure contacts the seabed. Once the base has touched down, the 2 cyclindrical buoyancy tanks will be vented, thus instantly applying the full weight of the gravity base to the sea floor and anchoring the ALC. Hyperbaric welding techniques will be used to tie the subsea pipeline into the expansion loop.

OSTI ID:
6111470
Journal Information:
Pet. Eng. Int.; (United States), Journal Name: Pet. Eng. Int.; (United States) Vol. 54:12; ISSN PEEID
Country of Publication:
United States
Language:
English