Shell cleared to drill in Alaska's Beaufort Sea Shell is poised to resume shallow drilling in the Chukchi after a large ice floe moved out of the area, Mr Smith said. It was able to drill for only one day before the ice drifted in, and plans to re-anchor the Noble Discoverer rig at its Burger prospect and restart drilling. All this 'top-hole' preparatory work would account for about half the time it takes to drill a well. "Drilling we complete this year will position us nicely for 2013," Mr Smith said. Environmentalists said Shell's setbacks this year demonstrate the pitfalls of offshore Arctic oil development. "Letting Shell do top-hole drilling and other preparatory activities when they are clearly not ready to respond to an oil spill is like telling a drunk driver that as long as he stays off the freeway everything should be OK," said Rebecca Noblin, Alaska director of the Center for Biological Diversity. Shell has spent an estimated $4.5bn in recent years on its plans to explore in Alaska's offshore frontier. It had targeted three wells in the Chukchi and two in the Beaufort this season, and a similar number next year. But those plans were scuttled with its failure to win certification of the required oil-spill barge and navigational hazards from sea ice. The oil-spill barge, the Arctic Challenger, has yet to be certified for seaworthiness, and some of its important oil-containment equipment was damaged during recent sea trials in the Puget Sound area. Shell announced on Monday that it would postpone efforts to drill into oil so it can repair the equipment and prepare for next year.