BP has outlined contingency plans for worst-case scenarios as it prepares to start drilling off the coast of Shetland.
Oil company BP had planned to start drilling in the North Uist area, around 80 miles north-west of Shetland, last year, but the launch date was postponed following the Deepwater Horizon leak.
In April 2010 an explosion at BP's Deepwater Horizon rig killed 11 workers and left 4.9 million barrels of oil pumping into the Gulf of Mexico, where it hit wildlife, coasts and fisheries.
It is understood one of the worst-case scenarios outlined in documents submitted to the government for the new well, which would start 1,300 metres below the sea's surface in the North Uist area, was a leak of 75,000 barrels a day.
Drilling is due to start next year once BP it has received approval.
"As part of our North Sea exploration programme, BP is planning to explore the North Uist prospect in the deep water West of Shetland in the first quarter of 2012," said a spokesman for BP.
"BP will be using the 'state-of-the-art' Stena Carron drillship, which has experience of deepwater drilling West of Shetland.
"Key lessons from the Deepwater Horizon incident have been incorporated into the overall planning for this well.
"BP is working closely with the UK regulator to provide the necessary assurance regarding preparations for this well."
WWF Scotland director Dr Richard Dixon said: "This plan shows that our fears about the potential for a massive oil spill from deepwater drilling west of Shetland were fully justified.
"Any significant oil spill in this area could present a major threat to fishing, tourism and wildlife.
"New deepwater drilling is just not worth the risk because we should be phasing out our use of oil not chasing ever more difficult sources."