The oil leak on a flow line system that serves the Shell-operated Gannet Alpha platform remains under control, with the well shut in, Shell said late Monday.
“It is not easy to quantify the total volume spilled but we estimate so far that it is around 216 tonnes (1,300 barrels),” said Glen Cayley, Technical Director of Shell’s exploration and production activities in Europe.
However, in terms of the volume on the surface, which changes from day to day, it is estimated today at about one tonne [approx. 6 barrels].
“This is a significant spill in the context of annual amounts of oil spilled in the North Sea. We care about the environment and we regret that the spill happened. We have taken it very seriously and responded promptly to it.”
Work continues to stop the oil remaining in the flowline from leaking. Shell said it estimates that the current rate of leaking is less than 5 barrels a day.
The sheen, which also changes from day to day, is 0.5 square kilometres in size. The spill is a light crude oil with a low wax content (API-36). There is also some hydraulic fluid in present.
Mr Cayley, speaking from Aberdeen, added, “The high winds and waves over the weekend have led to a substantial reduction in the size of the oil sheen as can be seen from the current levels on the water.
“We continue to expect that the oil sheen will disperse naturally due to wave action and that it will not reach the shore.”
A standby vessel, “Grampian Prince”, remains on station monitoring the area, with oil spill response equipment and dispersant available if required.
Shell’s emergency response team remains in place and we are working with the relevant authorities (DECC, MCA, Marine Scotland, Scottish Government) to manage the incident and minimise its environmental impact. We are also in contact with RSPB and other environmental agencies. We will be sharing our latest estimates with them as well as what we know about the nature of the oil, and the monitoring of wildlife.
Personnel on the platform are safe and the platform continues to operate.