In the week that Shell’s Kulluk drilling rig has been anchored in Alaska’s sheltered Kiliuda Bay, workers have scrutinized its exterior and studied conditions inside the 266-foot vessel.
Remote-operated vehicles and divers have been evaluating the hull of the conical drilling unit, which beached Dec. 31 on an uninhabited Alaskan island 30 miles away. That underwater assessment finished late Saturday, and workers are now analyzing data from the examination to determine what will happen next with the rig.
Officials with the unified command — comprising Shell, the Coast Guard and others — said they will provide more information when an assessment report is complete.
Depending on the documented damage, the Kulluk could undergo some repairs in its current location in Kiliuda Bay. For now, Shell is under orders to keep the unpropelled rig in the Kodiak Island bay until the Coast Guard signs off on further towing.
Shell had been using its purpose-built anchor handler Aiviq to tow the Kulluk across the frequently stormy Gulf of Alaska in late December when the vessels ran into problems. Amid high winds and waves, the Aiviq lost its tow line to the Kulluk and then its four engines failed. The Coast Guard and Shell sent more boats to help, but after four failed attempts to tow the Kulluk to safe harbor, first responders cut the rig loose and it grounded on Sitkalidak Island.
Salvage teams were able to pull the rig free Jan. 7, taking advantage of high tides and applying steadily increasing pressure to a tow line.
Questions have arisen about the reliability of the weather forecast that Shell used to predict what it called a “favorable” two-week window on Dec. 21, when the Kulluk set out on its two-week trek across the Gulf of Alaska. The National Weather Service uses forecasts that extend just a few days out, and its meteorologists say anything over 60 hours is unreliable.
The Kulluk itself is designed to thwart floating ice; its conical, upside-down-umbrella shape allows its hull to be lifted up by ice and then crash down on it, breaking and pushing it away. But that same configuration may make it ill-suited for journeys across stormy seas.
In an Anchorage Daily News article, Lisa Demer notes that even the high-powered Crowley Marine Services tugboat Alert used with tankers in Prince William Sound had trouble pulling the Kulluk during the tow emergency. Demer writes:
Towing the round Kulluk is nothing like towing a big oil tanker, which the Alert, as a Prince William Sound tanker escort vessel, is designed to do, said Charlie Nalen, Crowley Marine Services vice president of operations for Valdez. “This big saucer is turning. It’s an ungainly structure,” Nalen said. In contrast, a tanker will follow along behind a tug.