Buchan

Buchan Oil Field Redevelopment Profile

Location and Geology

• The Buchan oil field, also known as the Buchan Horst field, is located in the Outer Moray Firth within the UK Continental Shelf (UKCS) blocks 20/05a and 21/01a, approximately 115km northeast of the Aberdeenshire coast and 103.5km west of the UK/Norway median line.
• The field was discovered in 1974 by the well 21/1-1, which encountered a significant sweet and under-saturated oil column in fractured, Upper Old Red Sandstone.

Ownership and Partners

• The field is currently owned by NEO Energy (50% and operator), Serica Energy (30%), and Jersey Oil & Gas (20%).

History of Production

• The Buchan field was brought into production by BP in 1981 with nine development wells using the Buchan Alpha floating production vessel. It was later operated by Talisman Energy and then Repsol-Sinopec. Production ceased in 2017 due to certification limitations of the Buchan Alpha vessel.

Resources and Production

• The Buchan field is estimated to contain gross discovered oil and gas resources of approximately 70 MMboe (95% oil), making it one of the largest development projects in the UK North Sea.
• Over its initial 36 years of production, the field produced 148 MMbbl of 33 °API sweet crude oil and 37 Bscf of associated gas. At the time of shutdown, only around 29% of the estimated mid-case oil in place had been produced.
• The redevelopment project aims to produce an additional 70 million barrels of oil equivalent (mboe) with a peak production rate of approximately 35,000 barrels of oil equivalent per day.

Redevelopment Plan

• The redevelopment involves the drilling of up to five gas-lifted production wells and two water injection wells within the Buchan Horst field.
• New subsea production gathering infrastructure will be installed, tied back to the retrofitted 'Western Isles' Floating Production, Storage, and Offloading (FPSO) vessel. This FPSO will be modified to be 'electrification-ready' for potential connection to nearby floating wind power developments.
• The project includes the installation of subsea systems such as production, water injection, and gas lift pipelines, as well as an umbilical to connect the wells to the FPSO.

Infrastructure and Operations

• The 'Western Isles' FPSO will serve as the central oil and gas processing facility, with oil offloaded via shuttle tanker and excess gas exported via a new gas export pipeline. The gas export pipeline will be tied back to either the SAGE (Scottish Area Gas Evacuation) system or the FUKA (Frigg UK Association) pipeline system.
• The FPSO will be positioned approximately 1.5km away from the drilling centers to optimize well tie-backs.

Environmental and Decarbonisation Strategy

• The redevelopment is aligned with the UK’s energy transition strategy, focusing on a low-carbon development. The project involves reusing an existing FPSO and making it electrification-ready to connect to nearby floating wind power developments, thereby reducing the carbon footprint.

Project Timeline and Costs

• The final investment decision (FID) for the project is expected in the second half of 2024, with offshore operations slated to begin in the second quarter of 2025. First oil is anticipated in the fourth quarter of 2026.
• The redevelopment is estimated to require an investment of up to £950m ($1.2bn).

Contractors Involved

• Key contractors include Apollo Engineering Consultants for design/FEED engineering, Schlumberger, Petrofac, Proserv for wells, and Technip FMC for subsea operations. Sevan SSP is also involved in the FPSO front-end engineering design.

Greater Buchan Area (GBA) Development

• The Buchan redevelopment is part of a larger GBA development strategy, which includes the J2 West, J2 East, Verbier West, and Verbier East structures. These additional fields are planned to be tied back to the Buchan platform in subsequent phases, potentially extending the project’s plateau production period into the mid- to late-2030s.

This comprehensive redevelopment plan aims to maximize economic recovery from the Buchan field while aligning with the industry’s decarbonisation strategy.