The SeaRose is one of the oil industry's ocean goliaths, a massive vessel that floats on the North Atlantic waters over the White Rose field, some 350 kilometres southeast of St. John's. It stretches 272 metres long by 46 wide. It has enough on-board capacity to hold 90 crew and 940,000 barrels of oil.
But even triumphs of engineering like the SeaRose don't last forever, at least not without a break every now and then. So, 6½ years after it achieved first production in November of 2005, SeaRose is halting the flow of oil, disconnecting its equipment and steaming across the Atlantic for its very first tune-up.
Of course, it's a bit more complicated than that. Plans call for the SeaRose "off-station" to take 125 days. For Husky Energy Inc. , it's a major event, likely to remove nearly 4.5 million barrels of oil from its production. And there are risks, too. Like any vehicle servicing, it's possible problems will arise that could take longer than expected to fix. At 63,000 barrels lost every day without SeaRose in operation, any delay would be enormously costly to Husky, the majority partner in the project with Suncor Energy Inc.
For that reason, the company sweats the details. Planning for the complicated march of events started in May of 2010, fully two years ago. Husky expects to stop oil flow in coming days.
So how does it all work?
The SeaRose is designed to be able to quickly disconnect from the lines that feed it oil. In an emergency, it can take mere minutes. For a long off-station, though, the company allocates two to three weeks. Most of it is preparation – flushing lines, disposing of slops, preparing and inspecting equipment ahead of maintenance. The actual moment when the lines drop out of the ship is brief, lasting maybe an hour. "Then we've got to up anchors and we leave," said Paul McCloskey, senior vice-president for Husky in the Atlantic region. The disconnect, and reconnect months later, are specifically scheduled at times of year with "the best sea state and the best conditions."
It's roughly 3,500 kilometres from where SeaRose normally works to Belfast, and the Harland and Wolff shipyard where it will be lifted into dry dock. It's a famous shipyard – it was here that the Titanic was built – and also one of a small number around the world that can accept a vessel of SeaRose's size. Husky was unable to find a place in North America that could take the ship, in part because it has a central tower that is 80 metres high – enough that it couldn't fit under a bridge leading to one potential dock. The transatlantic sailing takes two weeks. The renovation and maintenance work starts in transit.
There's the important stuff, like making sure engines and propulsion systems are all ship-shape and maintained – something nearly impossible to do at sea. Some tank liners used for fire protection are removed, and workers will climb in to tanks for detailed inspections, looking for signs of corrosion. The entire hull gets covered in an anti-fouling paint, "one of our key protections," Mr. McCloskey said, against exterior rust. Software systems and controls get examined for possible updates. Then there's the more pedestrian stuff. Carpets get steam-cleaned, the interior is shined up.
The work is done by a mix of Husky's existing workers and outside contractors. Some 200 people are engaged in the job. Many are Husky employees who will fly to Northern Ireland while the SeaRose is at the dock, a period expected to last five weeks.
When it's done, the SeaRose sails back to offshore Newfoundland. It conducts sea trials on the way, to ensure the reliability of the vessel. Workers run a series of system checks to make sure everything is functional. Then the SeaRose latches back on to the depths of the sea, a process that takes roughly 12 hours.