The Njord A-platform in the Norwegian Sea
Statoil has also found it necessary to conduct special investigations at Visund, and this installation will therefore also be shut down today.
In the autumn of 2010, faults were discovered on some of the risers on the Njord A platform. An extraordinary inspection programme was therefore initiated. The inspection was performed visually by means of video camera that was sent down the risers.
Suspended production
Risers are pipes that carry oil and gas between the seabed and the installation. They are constructed of multiple layers of plastic and steel. The current challenges are limited to a specific type of riser technology. Internal damage of this type does not threaten the structural integrity of the risers, but over time it will reduce resistance to leakage. The risers are therefore immediately removed from operation when damage is detected.
“Damaged risers will be shut down until they have been repaired or replaced. The rest will be shut down until they have been inspected and found satisfactory,” says Jannicke Hilland, Head of Joint Operations.
Njord has been shut down since 1 April, whereas Visund will be shut down today. The shutdown results in suspended production on the fields. The total field production for Njord is some 70 000 barrels of oil equivalent (boe), whereas the production on the Visund field totals about 50 000 boe. The inspection is still in progress, and the production will be phased in as the risers have been inspected and approved.
The Norwegian Petroleum Directorate (NPD) and the Petroleum Safety Authority Norway (PSA) have been informed of the matter.
Other installations
Equivalent risers are in use also on other installations on the Norwegian continental shelf: Veslefrikk, Snorre A and B, Norne, Åsgard A and B and Glitne are Statoil-operated fields belonging to this category. On these installations, however, the risers are connected to a pipeline system on the seabed which reduces the risk of damage. There have been no known incidents or observations in the operating period that suggest damage to risers here.
Risers on all installations are subject to continuous monitoring and routine inspections in keeping with applicable inspection programmes.
Statoil had a meeting with the PSA this afternoon, describing the riser challenges. The company has also appointed a taskforce to identify actions that solve the operating challenges that the involved risers present. The taskforce addresses challenges across the Statoil group.