Bruce

Location and Geology

The Bruce field is situated in the North Sea, approximately 340 kilometers northeast of the city of Aberdeen, Scotland. The field consists of a complex structure with three main reservoirs: Turonian limestone (gas condensate), Bruce sandstone (oil and gas condensate), and Statfjord sandstone (oil and gas condensate). These reservoirs form a structural trap with several separate accumulations.

Development Phases

Phase I

The initial development of the Bruce field began with Phase I, which involved the construction of two bridge-linked platforms: the Process/Utilities/Quarters (PUQ) platform and the Drilling (D) platform. These platforms are connected by a 47-meter bridge. The D platform features a 9,400-ton three-level integrated deck and a 7,300-ton substructure jacket. The PUQ platform includes a 9,400-ton jacket supporting three major topside modules: a cellar deck, a production module, and an accommodation module with a helipad. The gas from the field is exported via a 6km, 32-inch diameter pipeline to the St Fergus Terminal, and oil is exported through a 248km, 24-inch diameter pipeline to the BP Unity platform, which connects to the Forties pipeline system.

Phase II

Phase II, also known as the Western Area Development (WAD), was sanctioned in February 1997 to develop the western part of the field. This phase involved a 13-well scheme, with eight wells tied directly to a manifold and five additional wells connected via a separate manifold or daisy-chain system. The project included the installation of a 213-ton subsea manifold and a 5.7km bundled pipeline system. A new CR platform was also provided with the capacity for an additional module, which was installed in 2004 to receive fluids from the Rhum field and to add gas compression facilities. This phase started production in 1998 with an initial flow rate of over 110 million standard cubic feet a day of gas and 14 million barrels a day of liquids.

Infrastructure and Operations

• Platforms and Wells: The D platform supports up to 21 post-installation wells and 11 pre-drilled platform wells through a 220-ton drilling template. The Phase II development included the installation of a 3,200-ton steel jacket and 2,750-ton topsides.

• Production Capacity: The maximum throughput for Phase II is set at 450 million standard cubic feet per day (mscf/d) of gas, 50 million barrels per day (bpd) of condensate, and 20 million bpd each of produced water and oil.

• Additional Facilities: The new module installed in 2004 on the CR platform included reception facilities for Rhum field fluids and additional gas compression facilities, enabling the recovery of an additional 100 billion standard cubic feet of gas from the Bruce field.

Investment and Production

The total investment in the Bruce field by the end of 1996 was £1.25 billion for Phase I, and with the addition of Phase II, the total investment rose to £1.6 billion. Production from Phase II started in 1998, and drilling continued until 2003. After 2003, production began to decline, and the field is expected to have available ullage in all parts of the platform facilities in the coming years.

Environmental and Operational Considerations

The project has been managed with considerations for extending the field's life and optimizing production. The addition of new facilities and the refurbishment of existing ones have been key in maintaining and enhancing production levels from the complex reservoir structure.