Subsea lowering by Jumbo

The foundations for the North Amethyst project, including two module support frames, were lowered to the Grand Banks sea floor at a depth of about 120 m. They will support subsea manifolds and flowlines that are part of a multiple well tie-back. The project was executed at the White Rose oilfield on behalf of a major Canadian energy company, said Jumbo.

The offshore works are part of programme of tasks being carried out by heavy lift vessel Jumbo Javelin, which is supporting offshore specialist Technip and its vessel Deep Pioneer.

The structures were loaded onto Jumbo Javelin at the port of Bay Bulls. The two 900 tonne capacity Huisman mast cranes were re-reeved from a 16-fall to a 4-fall configuration to reach the required depths.

Deep Pioneer had pre-installed the positioning guides at White Rose when Jumbo Javelin arrived to remove the sea-fastenings and connect the lift rigging. The lowering of the foundations required both vessels to work closely with each other using their GPS controlled DP2-systems.

A range of other structures were also lowered by Jumbo Javelin, all weighing 30 tonnes and above. First oil from the North Amethyst project is expected to flow at the end of 2009.