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.

The significant outlays required to ramp up such an operation were offset by the rising price of oil, which allowed oil companies to expand their operations without having to take on substantial volumes of debt.

But after several years of increases, global oil prices began to plateau in mid-2011 and have stayed relatively steady since then. In fact, 2013 experienced the least oil price volatility since 2006.

And oil prices in 2014 have remained remarkably consistent, especially taking into account record levels of global demand and the abundance of geopolitical tension around the globe, from Ukraine to Iraq and Syria.

via New Drilling Largely Driven By Debt.