Shell stirred controversy with its 2012 drilling program in the Chukchi Sea off northwest Alaska, the first there in more than two decades. Big oil is eager for another crack at drilling in the oil- and gas-rich Arctic offshore. But that renewed interest comes amid intense scrutiny in the aftermath of the Deepwater Horizon spill in the Gulf of Mexico in 2010. Encouraged by higher crude prices, better technology and steep costs that pose barriers to entry for all but the deepest pockets, heavyweights such as PLC, Chevron Corp. , ConocoPhillips , Exxon Mobil Corp. and Royal Dutch Shell PLC have spent billions of dollars to snap up offshore Arctic leases. The Arctic holds about one-third of the world’s untapped natural gas and 13% of as yet undiscovered crude, or roughly 90 billion barrels of oil, and more than three-quarters of those deposits are offshore, according to U.S. Geological […]