The Snøhvit field in the Barents Sea now provides gas to the world’s first LNG (liquefied natural gas) production site at which carbon dioxide is captured and stored.
The natural gas is produced by sub-sea solutions and transported via a 145 kilometre long multiphase pipeline to land.
On the island of Melkøya near Hammerfest, an LNG production site has been built, where the natural gas will be liquefied.
Ships will export the LNG at around -163 ºC to Europe and the USA.
Carbon dioxide has the undesirable property that it freezes to a solid at the temperature of LNG and can cause all kinds of operational problems, such as pipe blockage.
Therefore it is necessary to remove it prior to liquefaction. Just like the Sleipner field, it was decided to capture and store the CO2.
The carbon dioxide is captured with a conventional amine process.
A second 145 kilometre pipeline transports the captured carbon dioxide back to the Snøhvit field where it is injected into the geological layer of porous sandstone containing salt water, called the Tubåen formation. This layer lies 2,500 metres below the sea floor, safely below the gas containing layer.
Around 700,000 tonnes of carbon dioxide per year will be stored in this way. A monitoring programme has been set up for investigating the behaviour of carbon dioxide underground, partly financed by the European Union (EU).
Statoil is operator for the Snøhvit project which came on stream in October 2007.