Statfjord A

The incident

On the morning of 12 December 2007, around 4,000 m3 of crude oil were spilt into the North Sea at Statfjord A offshore oil platform, some 200 km west of the city of Bergen in Norway. Statfjord oil field is one of the largest Norwegian oil fields and is located near the border between British and Norwegian waters. The spill occurred while the shuttle tanker Navion Britannica was loading oil from a loading buoy.
 
The company StatoilHydro, operating the Statfjord oilfield, mobilised 8 vessels to observe and monitor the oil slick. A surveillance aircraft and two coast guard vessels were also mobilised.
 
 After a few hours, the slick was estimated to be 8 km long and 1 km wide and by late afternoon on 12 December its surface area covered an estimated 23 km². The following day, the slick was around 10 km long and 5 km wide, with an average thickness of less than 100 microns. The pollution was moving north-east and thought to be dissolving.

Response

Difficult weather conditions (winds of about 45 knots and waves up to 7 metres high) meant that the rescue and recovery vessels and tug boats sent on site had to be put on standby until the weather improved.
 
 The Norwegian Clean Seas Association for Operating Companies (NOFO) was rapidly alerted and was prepared to take action. Two oil spill response vessels were on site by the evening of the 12th (Havila Troll and Havila Runde) and two others (Stril Pioner and Far Star) arrived on the morning of the 13th. All the vessels were equipped with booms and skimmers provided by the NOFO. Two of the vessels were also equipped with dispersant spraying means. StatoilHydro decided not to disperse because of the natural dispersion of this crude oil predicted by behaviour modelling.
 
The initial strategy employed by StatoilHydro was to monitor the evolution of the pollution and to be ready to begin recovery operations as soon as conditions allowed it. On Friday 14 December, the waves had decreased to less than 3 metres high, allowing 2 containment and recovery systems to be used.
 
 The operations however soon came to a halt as the slicks were not thick enough to be recovered. Nevertheless, the vessels remained on site over the weekend to continue to monitor the slick, which was also under surveillance by satellite and aircraft.
 Additionally, a vessel with a ROV (Remote Operating Vehicle) on board was mobilised to examine the loading buoy and oil hose. Examination of the hose on 14 December by the Edda Fonn revealed a break in the hose between the seabed and the tanker connection.
 
 Extensive flights by surveillance aircraft LN-SFT, made available by the NCA (Norwegian Coastal Administration), on 15, 16 and 17 December did not detect any remaining oil, thus confirming predictions on natural dispersion. Overflights by helicopters carried out on 13 and 14 December by NINA (the Norwegian Institute for Nature Research) observed many birds but no dead birds were reported.

Environmental impact

Experts from SINTEF, with which Cedre cooperates on various research projects, and from NINA were put in charge of assessing environmental impact, by analysing water samples and avifauna map.
 Several accidents on oil platforms have previously been known to cause major spills. In 1977, a blow-out on the Bravo production platform in the Norwegian Ekofisk field caused 32,200 tonnes of oil to be released. In 1979, another explosion on the the drilling platform Ixtoc 1 in Mexico led to a major spill estimated at between 500,000 and 1,500,000 tonnes. In 1983, Iraqi bombings hit the Iranian offshore Nowruz wells, causing a spill of over 100,000 tonnes of oil at sea.