Shell drill ships headed to Alaska ANCHORAGE, Alaska, June 28 (UPI) -- Two drill ships are on their way to the Alaskan coast to explore for oil in arctic waters, said Shell. Shell announced that its Kulluk and Noble Discoverer drill ships left Seattle for Dutch Harbor, Alaska, to wait for sea ice to clear. "Upon arrival in Dutch Harbor, the fleet will await the opportunity to make entry into the Beaufort and Chukchi Seas," Pete Slaiby, vice president of Shell Alaska, said in a statement. Once open water allows, the rigs will sail to their respective theaters and commence exploratory drilling. U.S. Interior Secretary Ken Salazar told an arctic exploration forum in Norway this week that Shell's work off the Alaska coast will be conducted "under the closest oversight and most rigorous safety standards ever implemented." The company estimates that there may be as much as 25 billion barrels of oil off the Alaskan coast. Environmental groups have expressed concern about potential damage to the arctic ecosystem during energy development off the Alaskan coast.