Tuesday, 27 September 2011
Some signs were posted at driveway entrances along the highway, others were in the sides of rural buildings. Some signs were very large, others were just big enough to read as I drove by.
I've finally had the opportunity to look up this term. The following is from Wikepedia:
"Hydraulic fracturing, often called fracking, fracing[a] or hydrofracking, is the process of initiating and subsequently propagating a fracture in a rock layer, by means of a pressurized fluid, in order to release petroleum, natural gas, coal seam gas, or other substances for extraction. The fracturing, known colloquially as a frack job (or frac job), is done from a wellbore drilled into reservoir rock formations. The energy from the injection of a highly pressurized fluid, such as water, creates new channels in the rock which can increase the extraction rates and ultimate recovery of fossil fuels.
Hydraulic fractures may be natural or created by human activity, and are extended by internal fluid pressure which opens the fracture and causes it to extend through the rock. Natural hydraulic fractures include igneous dikes, sills and fracturing by ice as in frost weathering. Man-made fluid-driven fractures are formed at depth in a borehole and extend into targeted formations. The fracture width is typically maintained after the injection by introducing a proppant into the injected fluid. Proppant is a material, such as grains of sand, ceramic, or other particulates, that prevent the fractures from closing when the injection is stopped.
The practice of hydraulic fracturing has come under scrutiny internationally due to concerns about environmental and health safety, and has been suspended or banned in some countries." http://en.wikipedia.org/wiki/Hydraulic_fracturing