Ocean Kinetics - The Engineering Experts

Testing Shetland’s pollution response

A Hercules aircraft spraying dispersants while fishing boats and a Sullom Voe harbour tug pretent to deploying booms - Photo: Hans J Marter, Shetland News

LARGE stretches of Shetland’s coastline will almost inevitably be hit by an oil slick should a major oil spill take place in the busy new province west of the isles.

Yet those involved in a major pollution exercise, held in Aberdeen and Shetland during the last two days, said the UK was well prepared for a Deepwater Horizon-style accident, should it occur.

Exercise Sula was called for by Scotland’s first minister Alex Salmond, as well as MPs on the House of Commons energy and climate change committee and Greenpeace activists, who staged a protest in Shetland against deep sea drilling last September.

The scenario played out on Wednesday and Thursday involved around 6,000 barrels of oil escaping each day from a deep water well at Chevron’s Cambo Well Site, 86 miles to the west of the isles.

The national contingency plan was activated and oil spill response teams from Southampton were mobilised and sent to Shetland.

On the second day of the emergency the imaginary slick was already 58 by two kilometres wide and drifting towards Shetland.

Offshore oil spill fighting equipment would have deployed, including offshore skimmers, boom laying fishing boats and the specialist vessel Kingdom of Fife used to collect oil. Meanwhile a Hercules plane would be spraying dispersants.

By Day 10 around 60,000 barrels would have been spilled into the sea with the slick now measuring 163 by 78 kilometres, with around 940 barrels of oil washing ashore along Shetland’s west coast.

It would take at least six days for the oil industry to mobilise a capping stack, kept at Stonehaven, which would be expected to be on site after eight days. Meanwhile ‘well kill’ equipment could be on site by day six, while it would take around 90 days to drill a relief well.

Most of the exercise was played out in control rooms at the MCA and Chevron headquarters in Aberdeen, while an equipment demonstration took place at the Sullom Voe oil terminal in strong westerly winds that would have made the containment of any oil difficult.

Exercise director Colin Mulvana, a counter pollution salvage officer with the MCA, said that in his opinion the UK was well prepared for an oil spill out west as all the lessons from previous incidents had been learned and the agency was able to improve its response.

He added that the challenges compared to the Gulf of Mexico would be very different as the area was more open with higher waves and thicker oil.

“We are fighting the oil spill as much as humanly possible with all the equipment we have, with the offshore booming methods and the area dispersants. We can do no more than our utmost to try recovery and containment,” he said.

“I think we are very well prepared. We have all the cells in place, we all work together very well indeed, we have the equipment to mobilise and put in place to try to contain and recover as much as possible. I think we are in good shape.”

Marine scientist Martin Heubeck, who monitors seabirds for the oil terminal’s environmental advisory group SOTEAG, said that testing response times was a vital part of being prepared.

“An oil spill with this scenario is going to have a fairly devastating impact, there is no getting around that.

“There is only so much you can do with oil coming in from the open Atlantic, and coping with it as efficiently as possible is something that can be practised here. These exercises are designed to hone people’s skills and reaction times,” he said.

Scottish Parliament election, 6 May 2021