USA. 2012 – 2013
Hydraulic fracturing is the propagation of fractures in a rock layer caused by pumping in pressurized fluid. Hydraulic fractures may form naturally, as in the case of veins or dikes, or may be man-made in order to release petroleum, natural gas, coal seam gas, or other substances for extraction. Also known as fracking, or hydrofracking, this type of “frack job” is done from a wellbore drilled into reservoir rock formations. The energy from the injection of a highly pressurized fluid creates new channels in the rock, which can increase the extraction rates and ultimate recovery of fossil fuels.
The practice of hydraulic fracturing has come under scrutiny internationally due to concerns about the environmental impact, health, and safety, and has been suspended or banned in some countries.
Environmental concerns with hydraulic fracturing include the potential contamination of ground water, risks to air quality, the potential migration of gases and hydraulic fracturing chemicals to the surface, the potential mishandling of waste, and the health effects of these.