Quad204 is the £3bn redevelopment of the Schiehallion and Loyal fields, located 175 km west of Shetland and 15 km north of the Foinaven field. The project presents one of the most complex engineering challenges BP and its partners have ever undertaken
Schiehallion was discovered in 1993 and began producing in 1998, from five drill centres and through a floating production storage and offloading (FPSO) vessel of the same name. After 15 years of operating in harsh conditions and producing nearly 400 million barrels of oil, the Schiehallion FPSO required replacement to enable continued production from the field. At the same time, technological advances have increased understanding of the field and BP believes the greater Schiehallion area holds a further 450 million barrels of oil. To enable this resource to be tapped, BP approved the Quad204 project. The investment plan includes a new state-of-the-art FPSO, named Glen Lyon, renewal of much of the subsea infrastructure network to rejuvenate the field, and an extensive drilling programme. Field production was suspended at the start of 2013 and, in a unique operation in mid-2014, the Schiehallion FPSO was safely disconnected from the field and towed to Rotterdam, before her sale to a new owner. The project envisages that a substantial proportion of the offshore infrastructure recovered from the original development will also be recycled. The new FPSO, the Glen Lyon, arrived west Shetland in June 2016 and hook up and commissioning work is well under way. It has a storage capacity of 800,000 barrels of oil and is expected to process 130 thousand barrels of oil and 220 million standard cubic feet of gas per day. The Quad204 project will extend production beyond 2035. Key to this continued production will be the application of a new enhanced oil recovery scheme.