With planet Earth engaged in a heated race against global warming, "carbon capture and storage" has brought a ray of hope, and a Norwegian gas platform is leading the way.The Sleipner platform in the North Sea, a mammoth steel and cement structure, has successfully buried millions of tonnes of CO2 under the seabed for the past 12 years in a pioneering project.Using a simple metallic tube measuring 50 centimetres in diameter, the platform operator, Norwegian oil and gas group StatoilHydro, has injected some 10 million tonnes of CO2 into a deep saline aquifer one kilometre under the sea."We bury every year the same amount of CO2 as emitted by 300,000 to 400,000 cars," said Helge Smaamo, the manager of the Sleipner rig, a structure so large that the 240 employees ride three-wheeled scooters to get around.The project is far from a philanthropic initiative to save the climate: StatoilHydro decided to test the carbon capture and storage (CCS) idea 250 kilometres off the Norwegian coast for purely financial reasons.The natural gas extracted by Sleipner has a carbon dioxide content of nine per cent, almost four times the commercial quality target of 2.5 per cent, requiring the company to reduce the level by filtering it with amines on a platform adjacent to the main structure.Since it was already being filtered, the question was then whether to release the CO2 into the atmosphere or to capture it.A carbon tax imposed as of 1991 on Norway's offshore sector led the group to opt for the second solution, despite an initial cost of USD 100 million to drill a well and install a compressor, and annual operating costs of USD five million.
