Project Profile
Value: US$6,500 million
Location: Blocks 204/20 and 204/25, 175 km west of Shetland, UK Atlantic Margin
Water Depth: 350 - 450 metres
Recoverable reserves: > 400 million barrels
Average production: ~125 mboed (peak in 2018)
Start-up Year: 1998 (original field)
Start-up Year: May 2017 (Quad 204), until 2035
The Schiehallion field was discovered in 1993, some 15 kilometres to the east of the earlier Foinaven Field. The nearby Loyal accumulation, just to the north of Schiehallion was discovered in late 1994. The Schiehallion and Loyal fields lie predominantly in blocks 204/20 and 204/25, 175 km west of Shetland in a water depth of between 350 to 450 metres, with estimated recoverable reserves of some 450 - 600 million barrels. In April 1996, the UK government gave approval for a combined Schiehallion/Loyal development plan. Both fields produce to the Schiehallion FPSO vessel, owned on a divided rights basis, hence any available capacity in the vessel is owned separately by the vessel owners, through their interests in the two fields.
Development:
The water depth at Schiehallion dictates the use of subsea technology and a floating production system. To date, there have been in excess of 42 wells completed in the two fields, in five clusters. Oil and gas is delivered to the FPSO via steel pipelines and flexible risers to the FPSO for processing. Once on board the FPSO reservoir liquids are separated into oil, gas and water. Oil is evacuated by dedicated shuttle tanker, the Loch Rannoch, which takes the oil to the Sullom Voe terminal in Shetland. Gas is used to power the vessel, with any surplus being piped via the WOSPS (West of Shetland Pipeline System) system to the Sullom Voe terminal to the Magnus oil field where it is re-injected into the Magnus reservoir for enhanced oil recovery. Produced water is cleaned to below 30ppm oil before being re-injected back into the reservoir along with sea water injection.
Production:
Schiehallion began production in July 1998 and has achieved peak production rates of around 190 mbd. The Schiehallion FPSO is capable of processing around 200,000 barrels of oil a day and storing 900,000 barrels of oil.
The Glen Lyon FPSO will be able to process and export up to 130,000 barrels of oil a day and store up to 800,000 barrels.
Environment:
The Schiehallion and Loyal fields are located in an environmentally sensitive area. Both fields are certified to the international standard for environmental management, ISO 14001, and publish independently verified Environmental Statements annually.
Redevelopment Quad 204 project:
The Quad 204 project will replace the existing Schiehallion FPSO with a new build FPSO, producing from the Schiehallion and Loyal fields. The new build FPSO will deliver incremental reserves with increased operating efficiency and extend the field life to 2035+. The existing subsea infrastructure will be re-used and upgraded and up to 25 new infill wells will be drilled. BP commenced the execution phase of the Quad 204 project in the second quarter of 2011.
Decommissioning, part of the Quad 204 redevelopment:
BP has started preparations to decommission specific facilities associated with the Schiehallion and Loyal fields following regulatory approval from DECC for phase one of the programme.
The development comprises five drill centres with 54 wells, an extensive subsea infrastructure, the FPSO and a gas export pipeline to Sullom Voe terminal.
The scope of the phase one decommissioning programmes cover the pipelines and installations (mainly production flowlines and FPSO) not being reused as part of the redevelopment of the Schiehallion and Loyal Fields. Public consultation on the decommissioning of the Schiehallion and Loyal fields was completed in February 2013. The offshore removal and onshore disposal phase of the decommissioning project received regulatory approval in June 2013.
Operators:
BP: Operator with 33.35% interest
Shell: 44.90% interest
Siccar Point Energy: 11.75% interest
Chrysaor: 10% interest
Contractors:
Alderley Systems: Oil and gas metering systems
Aibel: VIEC (Vessel Internal Electrostatic Coalescer) technology
Aker Subsea Ltd: FEED and PMC for subsea field developments, life-of-field engineering support and other subsea engineering services
Aker Solutions: Provide subsea controls equipment for subsea trees, manifolds and subsea safety isolation valves as well as controls distribution assemblies
Babcock: Manufacture and deliver over 70 subsea structures
Consortium for decommissioning contract:
Veolia Environmental Services
Peterson Ltd
Emerson Process Management: Automation contractor & to provide its DeltaV Operator Training Solution
KBR: Feasibility Study and Engineering studies
Hyundai Heavy Industries (HHI): EPC - FPSO build
JP Kenny: Subsea engineering services
Odfjell Drilling: Build custom-made semi-submersible
OneSubsea: Supply subsea trees
Page Europa: Turnkey contract
SBM Offshore NV FEED: Detailed design of 9,100 tonne turret and FPSO vessel contract
Subsea 7: Subsea construction, inspection, repair, maintenance and redevelopment services
Technip Offshore UK Limited: EPC and Installation of risers, pre-commissioning, tie-ins and testing
Veripos: Provide precision positioning
Wood Group Kenny: Engineering, design and project management services
Roxtec: Contract to supply a range of bespoke products which will seal stainless steel tubes
Fugro: Contract to provide its wellhead and riser instrumentation service
Expro: Subsea contract with BP for the Quad 204 project in the UK North Sea involving the construction of a new floating production, storage and offloading unit west of the Shetland Isles to replace the existing Schiehallion installation. The seven-year, multi-million dollar contract will see the firm provide its latest design vertical Xmas tree landing string for the installation of BP\'s subsea completions.
Asset Guardian Solutions Ltd’s (AGSL): Contract to manage the process control software used to operate Quad 204. It will also feature a sizeable extension of the existing subsea system, with 15 new and replacement flow lines, and 21 new and replacement risers.
Amec Foster Wheeler: Three contracts by BP to provide services to the Glen Lyon FPSO vessel as part of the Quad 204 Project. The three reimbursable contracts are worth about US$47 million and will create 100 onshore and 50 offshore jobs. The hook up and commissioning contract, worth about US$40.5 million, will run through to June 2017. Amec Foster Wheeler will hook-up the new Glen Lyon FPSO to Schiehallion and Loyal fields as part of the BP’s Quad 204 redevelopment, extending the life of the two fields, enabling them to continue production beyond 2035. Amec Foster Wheeler will also provide follow-on engineering as part of a contract for any residual works that emerge during the transition from the yard in Korea to BP operations. This contract continues to June 2017. (December 2015)
EnerMech (UK) : Provided winch engineering, associated operations and materials for the FPSO’s main turret system riser winch handling system while the Glen Lyon was under construction and will provide ongoing field support during hook-up operations through to 2017. (August, 2016)
Ashtead Technology: Completed a subsea integrity management project to support Quad 204 redevelopment of the Schiehallion and Loyal fields. (August, 2016)
- deployed Deflection Monitoring System (DMS).
Teekay Offshore Partners: Three-year shuttle tanker contracts of affreightment (CoA) to transport the oil produced from the new Glen Lyon FPSO. (September, 2016)
Sparrows Group: Mechanical Handling and Crane Management contract.
Subcontractor:
Amarinth: Supply API 610 VS4 vertical sump pumps for HHI
BMT Scientific Marine Services: Provide an Integrated Marine Monitoring System for the new Quad 204 FPSO
Bowtech Products Ltd: Delivered Chain Stopper Monitoring System to SBM Offshore
Dyna-Mac: Topside modules, piperacks and turret for SBM
Daewoo Shipbuilding & Marine Engineering: Newbuild unit
Hamworthy: Supply an ST8 series treatment plant
NFM Technologies: Supply the mooring and riser installation for SBM Offshore
Oceaneering: Contract to supply umbilicals for Quad 204 Field development
Tritech International: Supply mooring line and riser monitoring technology for SBM Offshore
UTEC Geomarine: Geotechnical survey