With Hurricane Gonzalo bearing down on Newfoundland, how will it effect Canada's offshore oil rigs?

Saturday, October 18, 2014, 9:22 AM - Hurricanes sweeping past Atlantic Canada area always a concern, given the potential damage they can cause from powerful winds and flooding, but even those that miss landfall can still be a problem, especially for the men and women working on Canada's offshore oil rigs.

February 15, 1982, the  Ocean Ranger - designed as the largest offshore oil rig of its time - sank off the coast of Newfoundland due to rough seas from a powerful offshore storm. Waves up to 20 metres high battered the rig on the night of the 14th through to the early morning hours of the 15th, damaging its ballast system, ultimately causing it to list to the port side and then capsize just after 3 a.m. local time. All 84 crew members, including at least 67 Canadians, were lost. 

Fast-forward to 2009, when Hurricane Bill - then a weakening category 1 storm - forced the evacuation of 200 personnel from Exxon Mobil's Sable gas platform off the coast of Nova Scotia, while the rigs on the Grand Banks, off Newfoundland (Terra Nova, White Rose and the largest, Hibernia) remained in production. The Hibernia platform, which was specifically designed to withstand iceberg impacts up to 1 million tons without damage and up to 600 million tons with only minimal damage, is considered large enough to weather these powerful storms. At the time, Exxon spokeswoman Margot Bruce-O'Connell told Reuters in an emailthat Bill was "not expected to impact Hibernia operations."

A year later, in September 2010, with Hurricane Igor set to sweep right across the Grand Banks, Husky Energy evacuated two of their oil rigs, the Henry Goodrich and the Grand Banks, and left the production and storage vessel, Sea Rose, with only essential personnel on board. The larger rigs in the area, which are engineered to weather 1-in-100 year storms (Igor was considered a 1-in-50 year storm), remained staffed and in operation.

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Now, with Hurricane Gonzalo on a path to directly impact the Grand Banks, how will this effect the oil rigs there?

"We're confident Gonzalo will be more of a glancing blow than a direct hit on the Avalon. Gonzalo will be sideswiping the peninsula keeping the worst winds offshore," says Weather Network Chief Meteorologist Chris Scott. "This will be a dangerous storm for marine areas including the Grand Banks where waves could be as high as a 6-storey building."

Hibernia, the heaviest oil rig in the world, which is stationed in the Grand Banks, is rated to withstandthe impact of a million ton iceberg with only a scratch, and can still recover from anything up to a six million ton impact. Stationed in 80-metre deep water, on a 110-metre high gravity base structure that rests on the ocean floor, and with the platform of this massive structure stands over 200 metres above that, it's easy to see how the rig could stand up to a storm. Although there was an incident there in mid-Sept., involving two men who were nearly swept off the concrete base of the structure by waves, the rig itself has weathered storms in the area without incident since construction began on it in the 1990s.

Built to withstand rogue waves and sea ice, Hibernia in #Canada is the world's heaviest #offshore #oil platform. pic.twitter.com/yswgphcwJJ

— Chevron (@Chevron) May 9, 2014

The Terra Nova, a Floating, Production Storage and Offloading (FPSO) vessel, and specifically one of the largest ever built, is not only rated to withstand storms but due to it being a ship, rather than a drilling platform, it has more options open to it for avoiding the worst effects as these storms pass by.

As it stands now, Gonzalo is expected to drop up to 40 mm of rain across the Avalon Peninsula by Sunday morning, and the winds whipping across the Grand Banks could cause waves up to 15 metres high.

Smaller rigs and vessels in the area may feel more of the impacts of Gonzalo, though. According to the Gander Beacon , Husky Energy will apparently be halting production on the Grand Banks drill rig until the storm passes, but their Sea Rose production vessel will continue normal operations.

This could all change, of course. Gonzalo is only starting to affect Bermuda, well to the southwest of the Grand Banks, and it won't reach Newfoundland until early Sunday morning. The track of the storm is fairly well known at this time, but even a small shift at this time could ramp up the expected impacts from winds and waves, and prompt oil companies operating on the Grand Banks to quickly evacuate personnel before the storm arrives.