Monohull vessel extends well intervention water depth limit

A DP monohull vessel with riser will extend light well intervention capability from 1,300 to 10,000 ft (396 to 3,048 m) of water, said Cecilie Drange with Aker Oilfield Services on Wednesday at the Deep Offshore Technology International Conference in New Orleans.

Offshore staff

NEW ORLEANS -- A DP monohull vessel with riser will extend light well intervention capability from 1,300 to 10,000 ft (396 to 3,048 m) of water, said Cecilie Drange with Aker Oilfield Services on Wednesday at the Deep Offshore Technology International Conference in New Orleans.

AOS is building four vessels to this capacity, with the first one scheduled for delivery to Petrobras in 2010. The other three will be delivered sequentially through mid-2011.

The vessels are designed to carry out coiled tubing, wireline, construction, and testing services. They will be equipped with a four-part riser system, which extends its well intervention capacity to ultra deepwater, Cecilie explained. Well intervention without a riser is limited to 2,460 ft (750 m) of water. The design of its proprietary upper riser system, which sets it apart from conventional systems, helps push the technology beyond current limitations, she said.

The vessels will be fitted with a 24ft x 24ft (7m x 7m) moonpool capable of handling up to 450 metric tons (496 tons), 400-ton (363-metric-ton) active heave compensated crane, and capacity for up three ROVs on board. The vessels also can test a well flowing up to 20,000 b/d of oil.

Cecilie pointed out that the vessels can save 40-60% of the cost to operate one well.

2/4/2009

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