Fracking

Hydraulic fracturing – fracking – is a mining technique that, together with horizontal drilling, enables access to natural gas and petroleum deposits in deep rock formations that can’t be reached by more traditional methods. Liquid, generally water, is mixed with chemicals and sand and then injected under high pressure into a well. This makes tiny fractures in the rock along which gas, petroleum and the leftover liquid migrate into the well. Pressure is then removed, and small grains of sand or aluminum oxide are injected to keep the fractures open.