Independence Hub is an installation challenge

摘要

Specialized construction vessel performs a complex operational ballet in 8,000 ft (2,440 m) of water. The Independence Hub Facility is installed in Mississippi Canyon Block 920 in the Gulf of Mexico in 8,000 ft water depth. The Independence Hub facility consists of a semisubmersible hull with integrated topsides and a 12-line taut polyester mooring system, which supports the steel catenary risers (SCRs). The hull is a deep-draft, four column hull with an integral ring pontoon with a footprint of 232 ft by 232 ft (71 m by 71 m) by 160 ft (49 m) high. The topsides consist of a two-level deck measuring 140 ft by 220 ft (43 by 67 m) by 35 ft (11 m) high. Permanent facilities include a 16-man crew living quarters. The mooring system consists of a 12-leg, taut polyester mooring system. It includes suction piles, 100-ft (30.5 m) pile chain, subsea connector, 800-ft (244 m) bottom chain, polyester mooring rope in three segments totalling 10,800 ft (3,294 m) connected by H-links, two polyester test inserts and 1,000 ft (305 m) of platform chain. The SCRs connect a network of flow lines to the hub facility. The Independence Trail export SCR originates from the Hub facility with a 20-in. SCR. This 20-in. SCR holds the record of world's deepest and heaviest riser installation.