January 02 - On behalf of Acergy Australia, Jumbo Shipping has successfully completed the transportation of a massive disconnectable turret-mooring (DTM) buoy from Singapore to the Exmouth Gulf.
Furthermore, Jumbo also delivered sub-sea equipment to the sub-sea installation vessel Toisa Proteus, as well as returning demobilised equipment from the Toisa Proteus to Singapore.
Acergy Australia is the offshore installation contractor for the Van Gogh project, which is being developed by Apache Energy in the Exmouth sub-basin, offshore Northwest Australia. As part of the Vincent field, it lies in water depths of 340 to 370 metres and a floating production storage and offloading vessel (FPSO) will be used for production and storage of the oil. The FPSO will be moored to the DTM buoy, anchored to the seabed with nine anchors.
In addition to the normal engineering procedures, careful preparation was required as the DTM buoy could only be lifted from the top, using a single point connection. A special lifting device to suspend the 'ball tool' was designed in-house and manufactured under supervision of Jumbo in Singapore. A special grillage was designed to support and secure the buoy on deck. Extensive motion analyses together with finite element calculations were carried out to determine the loads exerted by the buoy on the main deck, caused by accelerations in rough seas.
Late last year, Jumbo Shipping's Fairlane arrived in Singapore to load the DTM buoy, which weighs 500 tonnes, using the vessel's two 400 tonnes mast cranes, before sailing to Dampier and, subsequently, the Exmouth Gulf to deliver the buoy to its final destination offshore.
Fairlane then sailed to the port of Henderson, near Perth, for the next phase of the project. Two sub-sea manifolds of respectively 160 and 180 tonnes, four riser bases weighing 100 tonnes and some smaller items were loaded. After returning to the gulf of Exmouth, Fairlane moored alongside Toisa Proteus and lifted the sub-sea equipment onto the main deck of the construction vessel, before returning demobilised equipment from Toisa Proteus to Singapore. The first oil from the Van Gogh field is expected to flow from March 2009.