LONDON (Reuters) - Britain’s worst oil spill for over a decade appeared to be entering its final stages, as the leak from Royal Dutch Shell’s faulty North Sea pipeline slowed to a trickle.
“The rate of leakage from the flowline to the Gannet platform continues to decline and currently stands at less than one barrel a day,” Glen Cayley, technical director of Shell’s European exploration and production activities, said on Tuesday.
Shell also said a change in weather conditions meant the oil on the water surface had grown in size. “A change in wave and wind conditions and general visibility does mean that the sheen affects a wider area of approximately 26 kilometers squared and is estimated to be between 1-10 tonnes in volume.
“The situation remains that there is no need for use of dispersant and we continue to expect that it will not reach the shore.”
Further detail emerged on Tuesday as Shell said oil seepage was continuing from a relief valve next to the main leak, dismissing reports of a second leak.
“The leak source remains the same. The initial release path was stopped on Thursday; however, the oil found a second pathway to the sea. There is no new leak,” Shell said.
A Scottish government spokesman said the impact of the spill on fishing had been reduced as the size of the spill had shrunk, and fishing continued as normal away from the affected area.
But environmental groups criticized the company for a lack of transparency and the delay before news of the spill was made public.
Sensitivities remain high about marine oil leaks and the availability of accurate information concerning their scale in the aftermath of BP’s massive Gulf of Mexico spill last year.
Reuters revealed on Saturday that the spill on Shell’s Gannet field, which it co-owns with Exxon Mobil Corp and which lies 180 km off the Scottish port of Aberdeen, had been leaking for two days before authorities or Shell spoke up.
Speaking in an interview with BBC Radio 4, Cayley defended the company’s initial silence, saying the leak was located among complicated underwater infrastructure.
“Only when we had confident information, really, did we want to share that, and since Friday we have issued daily bulletins and updates,” he said.
The government said Shell informed it of the oil leak on Wednesday, and its first focus was on ensuring Shell complied with its oil pollution emergency plan and took action to minimize the environmental impact before it publicized the spill.
“When that work had been started and the extent of the leak became clear, Shell informed the public,” Britain’s Department of Energy and Climate Change said in an emailed statement.
The company was not able to give an estimate of when it expects the pipeline to stop seeping oil, a spokesman said.
Shell said around 218 tonnes of oil, equivalent to 1,300 barrels, had leaked into the North Sea, but the rate at which it was flowing had been reducing since Wednesday, when the well was shut off.
Shell shares closed down 0.5 percent at 1,992 pence, compared with a European oil and gas sector up 0.5 percent.
“There are these types of leaks all the time, especially in mature basins with mature infrastructure. It will keep happening, but the industry is very well equipped,” said Sanford Bernstein analyst Oswald Clint.
Greenpeace spokesman Ben Ayliffe, echoing concerns expressed by the Royal Society for the Protection of Birds on Monday, said: “Any oil spill has the potential to significantly impact things like the birds, especially when we are this close to the breeding season.”
Shell said it was working with environmental groups and that observers had reported no visible damage to wildlife.
Additional reporting by Rosalba O'Brien; Editing by Will Waterman and Dan Lalor