Tension Leg Platform (TLP) Topsides
Oil was discovered in 1973 in the Hutton Field which is located in the East Shetland basin near the UK / Norway meridian. Rather than using a conventional fixed steel platform, Conoco developed the field using a prototype Tension Leg Platform (TLP) designed by Brown & Root/Vickers. This type of platform was based upon mounting drilling and processing Topsides facilities on a six column, semi-submersible Hull structure. The Hull was held in position by means of multiple tethers anchored to foundations on the sea bed. In offering some significant advantages over fixed platforms particularly in deep water environments, the TLP platform design was later extensively used worldwide in offshore developments of up to 1500 meters water depth
In June 1981 Conoco awarded McDermott Scotland a contract for the fabrication of the Hutton Topsides. The TLP Topsides was the largest integrated deck built at Ardersier and as such the project consumed a significant amount of the Yards space, equipment and people resources. The available images shown in the gallery have been ordered to give an indication of building block method and assembly sequence of the Topsides.
The TLP Topsides were loaded out in March 1984 and soon after the Topsides was mated with the hull structure, which was built by Hi-Fab (Highlands Fabricators) at Nigg. The integration of the two structures took place in the inner Moray Firth prior to installation in a water depth of 143 meters in the Hutton Field. Production commenced in August 1984 and continued until 2001 when production ceased.