Project Profile
Value: US$1.7 billion
Location: Northern North Sea, 340 km northeast of Aberdeen
Water Depth: 121 m
Current Production: Gas: 715 mmscf/d Oil: 41,000 bpd
Peak Production: Gas: 760 mmscf/d Oil: 67,000 bpd
Discovery Year: 1974
Start-up Year: May 1993
Bruce Field was discovered in June 1974 in acreage licensed to BHP in the 4th licensing round. Condensate, a light crude that exists as gas under reservoir conditions was found 4,000 metres below the seabed in a water depth of 121 metres.
Further drilling was largely unsuccessful. However, interest in the prospect was rekindled in early 1981 when BP discovered gas/condensate in an adjacent 5th round block in the centre, followed by a further discovery to the east by Total in 1984.
First production occurred in October 1998, with peak production rates from these facilities expected to be some 450 million standard cubic feet of gas and 45,000 barrels of hydrocarbon liquids per day. The production of gas from the Western Area has ensured that the Bruce Field maintains sales of gas at plateau rates beyond the year 2002. Keith field was tied back to Bruce in 2000.
The Bruce field is a complex structure of three reservoirs – Turonian limestone (gas condensate), Bruce sandstone (oil and gas condensate), and Statfjord sandstone (oil and gas condensate).
It is a structural trap consisting of several separate accumulations which could eventually need up to 40 wells to produce oil and gas at all reservoir levels. The phase II project was undertaken to fully exploit the reserves.
PHASE I
There are two platforms, designated the Process / Utilities / Quarters (PUQ) platform and the Drilling (D) platform, were linked by a 47m bridge. The D platform comprises a 9,400t three-level integrated deck, built by RGC. This supports a 7,300t, 36m x 46.3m substructure jacket, built by Dragados. Oil and gas from the Bruce reservoir is recovered by 11 pre-drilled platform wells, through a 220t drilling template. Up to 21 post-installation wells were specified for the D platform. The PUQ platform consists of a 9,400t jacket, supporting three major topside modules. These are the 8,000t, 55.75m x 32m x 16m cellar deck, built by Eiffel Construction in France, the 44m x 32m x 16m, 7,800t production module, built by Redpath at Teesside and the 43m x 13.4m x 20m, 2,500t accommodation module and helipad, built by SLP at Lowestoft.
PHASE II
Phase II of the development (previously known as Western Area Development, or WAD) developed the western part of the field. Sanction for this was granted in February 1997. Phase II accesses an additional 728 billion standard cubic feet of sales gas and 61 million barrels of oil and condensate. The life of phase II has been estimated at 25 years. The production fluids in this part of the reservoir contain less than 3ppm H2S, but 2.8mol% of CO2. Phase II adds a 3rd platform to accommodate additional gas compression facilities. This platform, known as the CR platform, is bridge linked to the two original Bruce Field Platforms.
Operator:
Serica Energy: Operator with 37% interest (bought from BP, transaction completion in 3Q 2018)
Total: 43.25% interest
BHP Biliton: 16% interest
Marubeni Oil & Gas: 3.75% interest
Contractors:
PSN: EPC contract
Dragados: Construction of the substructure jacket for the Drilling (D) platform
Eiffel Construction: Construction of the topside module, cellar deck, for the PUQ platform
Redpath: Construction of the production module for the PUQ platform
SLP Engineering Limited: Construction of the accommodation module for the PUQ platform
Odfjell Drilling: Platform Drilling Services contract
Bibby Offshore: a 15-day project which involves the supply of air and saturation diving support to perform operations including spool and flowline disconnection, evaluation and installation of conductor clamp guides, alignment clamp installation and modifications to a gas lift system. (July, 2016)
Subcontractors:
Frazer-Nash: Bruce gas turbine exhaust replacement project