Both of Shell's offshore drill rigs used during last year's oil exploration season to be transported to Asian shipyards for inspection and repair. The decision suggests the Kulluk and the Noble Discoverer -- Shell's only drilling rigs for the Arctic -- need major work and calls into further question whether Shell will be able to resume drilling in the Chukchi and Beaufort seas this year. Two federal investigations are under way into Shell's Alaska operations, reports the 'Anchorage Daily News'. With both of its Arctic rigs in need of repair, Shell hasn't made any decision on drilling this year. It must have two rigs at the ready, with one serving as a backup to drill a relief well in case of a blowout.