What Is Hydraulic Fracturing Or “Fracking”?

In hydraulic fracturing (“fracking”), large quantities of high-pressure fluids are pumped down a wellbore and into a rock (typically shale) formation, producing fractures. Various chemicals and materials called proppants, which are made of sand, ceramic pellets, or other small incompressible particles, are used to enlarge and hold open the fractures.

After the fluid injection and fracturing has occurred, internal pressure of the rock formation forces oil and gas and other fluids to return to the surface through the wellbore.