Major oil and gas companies are taking on an increasing share of debt in order to maintain drilling momentum, according to data from the U.S. Energy Information Administration.

Beginning around 2010, energy companies have been increasing their spending, particularly in the United States, as the tight oil revolution took off. Major firms snatched up acreage in oil-rich shale formations like the Bakken and the Eagle Ford and began drilling at a frenzied pace.

via New Drilling Largely Driven By Debt.