Unconventional wells, drilled deep into shale formations across the United States, continue to account for an increasing share of crude oil and natural gas production in the United States, according to the Energy Information Administration.

From 2004 to 2018, production from horizontal wells jumped from 15% to 96% of U.S. crude oil production in tight oil formations and from 14% to 97% of U.S. natural gas production in shale plays.

While horizontal wells have been a dominant source of shale gas and oil production since 2008 and 2010, respectively, the number of horizontal wells didn’t eclipse the number of vertical or conventional wells until 2017.

Learn more: Kallanish Energy > Horizontally drilled wells dominate U.S. O&G production