The Schiehallion field is located approximately 90 miles west of the Shetland Islands. It was discovered in 1993 with first production in 1998. Schiehallion is operated by BP (33.3%) with Shell (44.9%), Harbour Energy (10.0%) and Ithaca Energy (11.8%) holding non-operated interests. Ithaca Energy acquired its interest through its acquisition of Siccar Point Energy in June 2022.
The Schiehallion reservoir comprises excellent quality stacked Tertiary sands deposited by deep water gravity flows. The use of 4D seismic technologies has enabled better understanding of the field and as a result, the expected ultimate recoverable reserves have substantially increased from 340 million barrels in the original field development plan to over 850 million barrels, with over 450 million barrels of remaining recoverable oil reserves.
In 2011, the Schiehallion co-venturers sanctioned field redevelopment to unlock remaining reserves and extend the life of the field as part of BP’s Quad 204 project. A purpose-built harsh water FPSO, the Glen Lyon, replaced the old Schiehallion FPSO and much of the subsea infrastructure was also replaced. The field resumed production in May 2017. As well as re-using the existing well stock of 44 producers and injectors, an ongoing multi-year drilling programme will add new wells to the field.