Aiviq: Pride of Shell’s Alaskan drilling fleetOct 16, 2012 01:33 PM
Photos by Brian Gauvin
Aiviq is a critical part of Shell’s offshore operations and the most advanced and sophisticated ice-class vessel to work in the Arctic.
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In the flotilla of 20 vessels that gathered at Dutch Harbor, Alaska, this summer to spearhead Shell’s six-year, $4.5 billion bid to open the Chukchi and Beaufort seas to drilling, a brand-new ship stood out, gleaming in blue and white.
The vessel was Aiviq, a 360-foot ice-class anchor handler built by Edison Chouest Offshore at a reported cost of $200 million. Two Chouest yards were involved; North American Shipbuilding put together the hull in Larose, La., and LaShip in Houma fabricated the upper house and handled final assembly.
In its first few weeks at work in Alaska it successfully positioned 16 anchors on the sea floor.
Aiviq was designed by Chouest’s Gary Rook and was the product of more than 2 million work hours. It’s the largest, most advanced vessel Chouest has ever built and can work equally well in hostile, cold-weather environments and in 10,000 feet of water in the tropics.
“The design question for the vessel was to be able to operate in minus-40 degrees,” Gary Chouest, the company’s CEO, said at the vessel’s christening in Port Fourchon, La. “At the same time, it’s capable of operating in the deepest waters of the world where oil and gas activity exist today.”
Chouest launched its first icebreaker, Nathaniel B. Palmer, for the National Science Foundation 30 years ago. For Aiviq, it tapped Capt. Joe Borkowski, a Palmer veteran with 23 years’ experience in the Antarctic.
Endurance is a key asset of the vessel. Pete Slaiby, vice president of Shell Alaska, says Aiviq can go it alone for about 100 days; it even has its own hospital, with a 22-bed recovery area. And survivability is paramount. Pointing to one of two 64-person fully enclosed, Arctic-class lifeboats, Borkowski said: “It’s a boat in a box. First in the U.S.”
Gary Chouest at the vessel’s christening.
On station in support of a rig or drillship, Aiviq’s primary mission is setting and removing anchors. It also offers extensive berthing; the guest space alone, set in a big U in the stern, houses 64 beds, 64 lockers and 64 survival suits. Its secondary task is ice management — gently nudging drifting floes away from the scene of the action. It can also help other purpose-built vessels recover oil in case of an accident.
Aiviq can travel at 5 knots in up to a meter of ice; forward of the engine room there are very strong structural supports, and all exposed piping is protected from stress in ice operations. Two heeling pumps help the ship break ice. “When the vessel runs up on ice, it sloshes water back and forth,” said Chief Engineer Les Amoss.
Aiviq measures 360 feet 8 inches by 80 feet with a depth of 34 feet. The normal draft is 26 feet, slightly less in maximum ice. The main engines are four Caterpillar C280-12 diesels rated at 5,444 bhp each driving two 4,600-mm-diameter controllable-pitch propellers in nozzles via Flender twin-in/single-out gearboxes.
Thruster power is huge. The bow alone has two Brunvoll FU100 2,450-mm thrusters rated at 1,500 kW plus a Rolls-Royce 2,000-kW fold-down. At the stern are two Brunvoll FU80 LTA 2,000-mm thrusters rated at 1,050 kW. There are four Cat 3512C gensets rated at 1,700 kW, two 2,000-kW shaft generators and two Cat C32 910-kW emergency gensets.