Oil and gas giant Exxon Mobil Corp. is suggesting that a better way to frack will double the amount of oil it can pump from shale fields.

“There’s just a lot of oil being left in the ground,” Chief Executive Officer Darren Woods said. “Fracking’s been around for a really long time, but the science of fracking is not well understood.”

Source: Phoenix Law/CC BY-NC-ND 2.0

Hydraulic fracturing, or fracking, is the process of blasting water, sand and chemicals underground to break apart rock and keep it propped open for oil to flow out. Though the technology has given rise to the U.S. shale boom, only about 10% of the oil in a reservoir is recovered using current techniques. Better drilling and fracking methods may prove critical as output growth from shale fields slows.

As such, Exxon Mobil is working on two specific areas to improve fracking, Woods said. It wants to be able to frack more precisely along the well so that more oil-soaked rock is getting drained. It also wants to keep the cracks open longer to boost the flow of oil. Sand is the primary method today to prevent fractures from closing up.

“That in my mind is where the first wave of technology will come into that field,” Woods explained. “We think we’ve got some promising technologies to employ there that will significantly improve our recovery.”