Production Platform Jacket & Piles
In 1975 Conoco discovered oil in Murchison field which is in a location 150 km north-east of Shetland and spans the UK/Norwegian sector median line. Plans to develop the field were based upon installing a large fixed platform with integrated drilling and production facilities.
In 1977 Conoco awarded the Ardersier Yard a contract to build an 8-leg Jacket with Piles for Murchison, with delivery planned for the summer of 1979. At over 27,500 Tonnes, Murchison was more than 10,000 Tonnes heavier than the Yard’s previous large eight leg Jackets but had to be built within a similar time frame. Critical to delivering to the aggressive schedule was the fabrication and installation of the 1,600 Tonne “bottle-leg” sections in a single piece. The “bottle leg” sections being the cluster of sleeves at the base of the outer legs which formed a grouted connection between the Jacket and the foundation Piles. Fabrication of the four bottles was subcontracted to a Japanese company and plans were made to utilise a new-build lifting portal (Nessie) to offload the bottle assemblies from the delivery vessel and to lift them into place. During testing however, the lifting portal failed and became a total write-off.
Whilst a major setback at the time, recovery of the schedule was achieved by using a specially designed lifting tower with strand jacks to lift the bottles into place. After load out and sail-away from the Yard, the platform was installed as planned in summer 1979 and first oil produced in September 1980,
De-commissioning of the platform commenced in 2013 with the plugging of wells and production stopped finally in March 2014.