Kulluk on Dec. 31 was being towed to Seattle for maintenance but was cut loose due to weather conditions and struck ground offshore Alaska. Though the vessel contained petroleum products, there were no reports of sheen from the incident.
Shell said, in an operational update, that Kulluk was in tow at an average speed of 4.8 miles per hour. It's destined for Kiliuda Bay, about 30 miles north of the bay in which the vessel was grounded.
"A 10-member salvage crew and one Shell representative are on board the Kulluk and will remain on the drilling unit throughout the tow," Shell said.
Kulluk was part of Shell's efforts to explore for oil and natural gas in the arctic waters of the Chukchi and Beaufort seas off northern Alaska. Shell last year received approval from the federal government to start an arctic campaign, though equipment issues and weather complicated the efforts.
Democratic lawmakers in the U.S. House of Representatives last week called on the Department of Interior and U.S. Coast Guard to investigate the incident.
"The recent grounding of Shell's Kulluk oil rig amplifies the risks of drilling in the arctic," members of the House Sustainable Energy and Environment Coalition said in a statement.