What is “fracking?”

While it was relatively unheard of a decade ago, today more than 90% of all new onshore oil and gas development in the U.S. involves some form of hydraulic fracturing. Though hydraulic fracturing has revolutionized oil and gas production in the United States, it is only one part of the process.

The natural gas revolution in four simple steps

1. A well is typically drilled thousands of feet down to access natural gas (methane) trapped within a layer of rock called shale.
2. Once at the proper depth, the drill bit moves horizontally across the layer of shale to create a small shaft in a process known as "horizontal drilling."
3. Small explosive charges are detonated along this shaft to open fissures in the shale.
4. Finally, a mix of water, sand, and chemicals is injected into the fissures widening them, and releasing the natural gas which flows back through the well to the surface. It is these last two steps that are properly understood as "hydraulic fracturing."

See more

• Why is natural gas important?
• Five areas of concern