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.
Location of the Statfjord oil field
(Source: StatoilHydro)
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.
Name: Statfjord A
Date: 12 December 2007
Location: Norway
Accident area: North Sea
Cause of spill: loading operation
Type of pollutant: crude oil
Quantity spilled: 4,000 m3
Structure type: offshore platform
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.
Statfjord A platform
(Source: Marit Hommedal/StatoilHydro)
See also
Links
Last update: May 2011