The unstaffed lobby of the North Dakota regional headquarters of oil producer Occidental Petroleum Corp...
The unstaffed lobby of the North Dakota regional headquarters of oil producer Occidental Petroleum Corp is seen in Dickinson, North Dakota in this October 14, 2015 photo. Occidental, the fourth-largest U.S. oil producer, built the regional office for more than $8 million less than three years ago as it spent lavishly to expand in the state. Occidental has agreed to sell all of its North Dakota shale oil acreage and assets to private equity fund Lime Rock Resources in a deal worth around $500 million, according to sources familiar with the matter. REUTERS/Ernest Scheyder