Page 110: of Offshore Engineer Magazine (May/Jun 2015)

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Red Hawk spar

Gulf of Mexico and the frst spar turned into an artifcial fies home reef or “reefed” FPS hull and the deepest foating platform decommissioned in

InterMoor’s Dusan Curic discusses the decommissioning the Gulf of Mexico. All these are syn- onyms for Red Hawk Spar, a former FPU of Anadarko Petroleum’s Red Hawk spar in the US Gulf of installed by Kerr McGee, an Anadarko

Mexico, a job that involved several industry frsts.

predecessor company, and now an artifcial reef in Eugene Island block 384 he world’s frst, and so far only, barges. Anchor handling tug supply offshore Louisiana.

cell spar is also the frst spar (AHTS) vessels were utilized instead of

T Red Hawk’s productive years upended and moored without the conventional methodology. This is using construction vessels or derrick the frst producing spar decommissioned Red Hawk spar began its frst life in 2004 when it was installed in 5300ft of water in Garden Banks block 876 by horizontal wet towing from Ingleside,

Texas, upended to a vertical position and moored using a chain-polyester- chain system with suction pile anchors.

Anadarko found itself in a position as the lease holder on a feld that was soon to expire. A decision on the platform’s decommissioning had to be made. When the time came to decommission the spar, it was determined that simply reversing the steps from the installation proce- dure–ballast the hull to a horizontal attitude and tow it back to shore–was not the best solution.

Decommissioning

A totally different approach was taken thanks to Anadarko’s experience with fxed platforms which had been included in the US Bureau of Safety and Environmental Enforcement (BSEE)

Rigs-to-Reefs program. When a suitable location was found in 430ft deep Eugene

Island block 384 and after BSEE and the

Louisiana Department of Wildlife and

Fisheries agreed that marine life would beneft from converting the Red Hawk hull into an artifcial reef, the planning phase for the decommissioning was ready to begin.

Anadarko teamed up with two main contractors, Versabar for the topsides lift and InterMoor, an Acteon company, for integrated decommissioning engineering and offshore execution. InterMoor’s scope included ballasting and deballasting of the

Red Hawk hull, mooring disconnect and recovery, hull tow and fnally, hull reefng

Top: With holes cut into the hull, Red Hawk spar is being tipped underwater. at EI384. Ballasting and deballasting were

Above: Red Hawk Spar was towed vertically to its reefng site. Images from InterMoor.

performed remotely from McDermott’s

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