Greenhouse store staying sealed

New seismic data from the Utsira formation in the North Sea indicate that the carbon dioxide being pumped into it is not leaking out, but is spreading through the structure as expected, reports StatoilHydro.

Sleipner Gas Field. Photo: ioc3.unesco.org

Thirteen years have passed since StatoilHydro and the Sleipner gas field partners Exxon Mobil and Total decided to capture carbon dioxide and store it beneath the seabed. The reason for the decision was the carbon dioxide emission fee introduced by Norwegian authorities in 1993, which made it more profitable to capture and store the carbon dioxide than to pay the emission fee.

StatoilHydro extracts 2,600 tonnes of the greenhouse gas from Sleipner West production for storage 1,000 metres beneath the seabed, rather than releasing it to the air. More than 10 million tonnes of carbon dioxide have been injected into the Utsira sandstone formation since the autumn of 1996.

StatoilHydro conducts extensive monitoring and control of the carbon dioxide in the sub-surface store, and collects four-dimensional seismic data every other year. Intended to identify the way the gas is behaving in the formation, this information from the 2008 survey has now been analysed.

The seven geophysical measurements conducted to date show a stable trend, with the carbon dioxide spreading upwards from the injection site and slowly through the rock.

“Twelve years of data and seven surveys confirm the indications from the models and forecasts,” says Eli Aamot, head of the new energy and ideas research programme in StatoilHydro.

“Our CCS programme in the Sleipner area has provided a groundbreaking demonstration that the sub-surface can contain the gas for a long time,” states Aamot.

For more information visit: StatoilHydro.com