On the Heidrun platform in the Norwegian Sea, Statoil is carrying out tests to determine if it is possible to reinject produced water underground.
The production wells on the field need pressure support, and produced water is an alternative to seawater for injection purposes.
The solution has major environmental gains. There will be no harmful discharge of the produced water into the sea. The method is also favourable for oil production since it reduces the amount of scaling compared to salt water. This reduces the need for well treatment and thereby also the strain on the environment through reduced energy and chemical consumption.
“If the test is a success we may invest in permanent facilities to enable the injection of all the water that is produced on the field,” says Sten Paltiel, environmental coordinator for Heidrun.
The pump system that was used in the test is surplus equipment from the development of the Åsgard field in the Norwegian Sea.
The injection test began on 5 February in well A-43. Currently, 2500 cubic metres of water per day are being injected, which is equivalent to 40 per cent of the water produced on Heidrun.
Statoil has most experience of injecting produced water on the Yme field in the North Sea. The field, which will be shut down in the summer, came on stream in 1996.