In June 2011, Jumbo’s DP2 Offshore Heavy Lift Vessel Fairplayer installed four subsea protection structures for production flowlines at 600m water depth in the Laggan & Tormore fields in the UK. These gas condensate fields, owned by Total and Dong Energy, are located 125km north-west of the Shetland Islands. This region contains approximately 17% of the remaining UK oil and gas reserves. The subcontract, commissioned by client Allseas, will combine transport and installation, Jumbo Offshore’s hallmark.
The fields’ subsea production and pipeline system is the deepest system in UK waters and includes two 18-inch production flowlines. The flowlines will connect the subsea production facilities to the onshore processing terminal at Sullom Voe (Shetland). The two flowlines require protection structures at the Tormore starting point and at the Laggan tie-in location.
HLV Fairplayer mobilized in Rotterdam (The Netherlands), e.g. taking temporary accommodation units onboard (maximum 65 persons) and preparing its Deepwater Deployment System (DDS). The four structures (composed of six elements) vary in weight from 180 tonnes to 270 tonnes and measure 38 x 21 x 6m. Fairplayer made two consecutive trips, and on each trip Jumbo transported and installed two structures in three lifts. Using its DDS, the structures were installed at 600m water depth in a single voyage.
The Laggan & Tormore subsea installation project confirms Jumbo Offshore’s ‘added-value concept’ of providing a single solution for loading, transporting and installing subsea structures in water depths up to 3,000 m. Once again, Fairplayer’s DP2 capabilities, Deepwater Deployment System and twin 900-tonne mast cranes prove to be constructive to a high-technology offshore project.
After project completion Jumbo plans to keep HLV Fairplayer in the North Sea area for other installation opportunities.
Jumbo Offshore has access to 12 Heavy Lift Vessels, two of which are DP2-class: Jumbo Javelin and Fairplayer. These DP2-vessels can be used for subsea installation work, including the installation of subsea structures and mooring systems for floating production systems. Fairplayer is equipped with a Deepwater Deployment System (DDS). With this DDS Jumbo Offshore is able to lift large and heavy structures from deck and place them on the seabed without the need for subsea transfer. Typical installation possibilities are: 1,000 tonnes at 1,000m, 600 tonnes at 1,700m and 200 tonnes at 3,000m.