Gullfaks A. Photo: Øyvind Hagen, Statoil
“We addressed two topics in the meeting, specifically those relating to well integrity and pressure build-up in the Shetland formation,” says head of Gullfaks, Gunnar Nakken.
“Studies carried out in 2010 show that the pressure in the Shetland layer is sufficiently high that the formation strength alone does not constitute a full barrier against leakage to the sea bed. However, in our view, the sands in the Hordaland formation, which lie above the Shetland and Lista formations, have sufficient capacity to compensate for this. We do not therefore consider it probable that leaks will occur to the formations above the Hordaland layer,” he says.
“During the autumn of 2010 we have closed down 20 wells, mainly water injection wells, after a review of the integrity of all the wells in the field. As a consequence of reduced water injection (pressure support), a further 30 wells were closed down in 2010 to maintain the pressure balance in the field. We are now continuing to work systematically to get as many as possible of these wells into production again,” says Nakken.
“Statoil believes that our operations at Gullfaks are safe and responsible. Wells with problems relating to their integrity have been closed down. We are monitoring the pressure in all wells at the field in order to continually confirm our evaluations and conclusions,” he says.
“We are keeping the PSA, the Norwegian Petroleum Directorate, partners, employee representatives and the safety organisation updated on developments at Gullfaks, so that they are reassured that we have responsible and safe operations at the field at all times.”
Chief health and safety representative Terje Herland at Gullfaks has been involved in the preceding process and also during earlier evaluations of Shetland.
“I consider the situation now to be better and I am not concerned for the safety of personnel at the field,” says Herland.