North Sea developments in recent years have featured a couple of minimal facility designs, Sea Harvester and Trident.

Trident was first used for Shell's Skiff project in early 2000 and collected an award from the British construction industry for its design. Shell has since used the same platform design for its Brigantine gas project.

Trident was developed by Shell engineers in Lowestoft, United Kingdom, one of the main centers for southern North Sea operations. Shell's ultra-minimal design is estimated to be between a third and half the cost of a more traditional gas platform. It features a cross-braced steel structure weighing 400 tonnes supporting1,500 tonnes topsides. Conductors from the four gas wells are used as foundation piles and skirt piles are added to secure the Trident platform in place. Installation involves driving and drilling piles into the subsurface and the jacket is installed without a heavy lift crane barge.

KYE Engineering in Lowestoft, which previously built the Skiff facility, won a US $7.5 million contract for engineering, procurement and construction for the two Brigantine BG and BR platforms in block 48/18 and 48/19 about 3.1 miles (5 km) northeast of Shell's Indefatigable field. They have no helideck, and are designed for annual boat-access only. Since they are so small, there is no "safe area" within them. For Brigantine, special minimal-maintenance Emergency Shutdown Systems were supplied by Yokogawa within certified explosion proof-cases to provide basic asset and personnel protection. Each of the Brigantine platforms was designed for a water depth of 85 ft (26 m) and the towers are 470 ft (143 m) high. Electrical power is provided from Shell's nearby Corvette installation.

This year will see the installation of another new minimal facility to tap the Goldeneye field where topsides provide only essential services.

Again, a normally unattended installation design has been selected for $495 million project which allows a full wellstream transfer from the field in U.K. block 14/29a directly back to shore - the first time this has been done. There is no offshore fluids processing on the Goldeneye facility. Gas, condensate and produced water will flow directly back to shore via a 63 mile (101 km) 20-in. export pipeline to a new onshore treatment plant under construction at St. Fergus, south of Aberdeen, Scotland, making it the longest tieback in the North Sea, Shell claimed when Goldeneye was approved last year. At the treatment plant, field control, slug-catcher, gas liquids separation, plus dehydration, hydrate and corrosion inhibitor recovery and re-delivery and future depletion compression services will be provided. Foster Wheeler won a $100 million contract to construct the terminal. The platform will provide only well operations, a manifold and metering, oil and water detection, wellstream sampling, sand control, the capability for pig-launching and formation water removal. Control of well chokes and manifolds will be achieved by satellite communication from shore. Production of up to 300 MMcf/d of gas and 10,000 b/d of condensate is due by 2004 between 7 and 10 years.

Aker Verdal in Norway won a $16.5 million contract in March 2002 to build the Goldeneye jacket and SLP Engineering was selected for a $21.45 million deck and topsides fabrications contract.

Conoco's Saturn development in UK southern North Sea block 48/10b is a slightly heavier minimal facility platform, with a 560 tonne jacket. This development follows the pattern set by the ConocoPhillips for its earlier Viscount gas project in the southern North Sea. Both used the Sea Harvester platform design built under license from the United States by SLP Engineering.

Saturn featured a five-drilling slot facility capable of taking 30-in. conductors, a 14-in. gas production riser and 4-in. methanol supply risers. Space for two further 10-in. gas risers and two 10-in. J tubes for subsequent developments were included in the design. Topsides, weighing 350 tonnes, including 240 tonnes of steel work, provides emergency accommodation for up to 12. The deck is 49 ft (15 m) wide, 65 ft (20 m) long and 26 ft (8 m) high.

Minimal instrumentation is installed for unmanned operation. While hydraulic and wellhead control panels are easily accessible, each well on the platform has surface-controlled hydraulically actuated Downhole Safety Valves set between 300 ft to 400 ft (91 m to 121 m) below the mudline. Space for subsequent installation of water removal or test-sampling kit is provided.
In the Eastern Irish Sea, Burlington Resources is developing a 250bcf five-field sour gas complex with a minimal facility installation over the Calder field, which will provide a gas gathering hub for four others, Darwen, Crossans, Hodder and Asland. These are to be connected via subsea wells, and take their name from English rivers, hence the collective name, for the Rivers complex. Genesis Engineering consultants developed the design for Calder.

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