Preparing for floating electrification

The Gjøa platform in the North Sea will be the first floating platform to get its electricity from the mainland. This will mean a reduction in emissions to the environment of 250,000 tonnes of carbon dioxide per year.

The Gjøa platform in the North Sea will be the first floating platform to get its electricity from the mainland. This will mean a reduction in emissions to the environment of 250,000 tonnes of carbon dioxide per year.
 
Illustration: The Gjøa field in the North Sea is expected to come on stream in 2010.
 
"Electrifying new installations on the Norwegian continental shelf is one of the most important measures to reduce further carbon emissions from Norwegian oil and gas production," says Trude Sundset, StatoilHydro's vice president for the environment and climate.

"With the electrification of the Troll A platform and Kollsnes and the decision to electrify Gjøa, StatoilHydro is a front runner with a view to reducing emissions of nitrogen oxides and carbon dioxide," Ms Sundset believes.

Developing new cable
Gjøa is expected to come on stream in 2010. A cable running from the new power plant at Mongstad, north of Bergen, will supply the platform with electricity.
"The cable has to be able to tolerate a lot of movement and together with contractor ABB, a new high-tension submarine line is being laid," says Kjetel Digre, project director for the Gjøa field development.

"The alternative to this would have been a traditional solution with gas turbines on the platform producing power. By electrifying the platform with a cable instead, the energy that Gjøa needs will be produced with the environmental standard of the new Mongstad power plant. This gives high energy efficiency and reduced emissions of carbon dioxide, nitrogen oxides and volatile organic compounds (VOC) as compared with the alternative solution," explains Mr Digre.

Biggest offshore project
Gjøa, including the Vega satellite development, is the largest project in the North Sea today. Investments in the fields are about NOK 37 billion.

With Gjøa, a new part of the North Sea is being opened for oil and gas production. StatoilHydro is operator in the development phase of Gjøa. Gaz de France Suez will assume operatorship at production start up.

The Gjøa field is being developed with a semi-submersible production platform and five sub-sea templates. Gjøa's recoverable reserves are some 82 million barrels of oil and condensate and roughly 40 billion standard cubic metres of gas. Vega's recoverable reserves are estimated at 26 million barrels of condensate and 18 billion standard cubic metres of gas.

Gjøa partners: StatoilHydro (development operator - 20%), Gaz de France Suez (production operator - 30%), Petoro (30%), Shell (12%) and RWE Dea (8

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