The process of extracting natural gas or oil from underground shale by fracturing the rock with a mixture of water, sand and chemicals applied under pressure. That’s a pretty straightforward fracking definition. A relatively new method of drilling, fracking has generated a great deal of controversy amid fears that it may have a detrimental impact on the environment.
The fracking process involves drilling downwards at first, and then horizontally, sometimes for miles, to reach natural gas or oil deposits trapped inside the rock on a molecular level. Then the well is cased and cemented. Small perforations are made in the horizontal section of the pipe and what’s called slickwater, a mixture of water, sand and chemicals, is pumped through the holes and into the rock causing micro-fractures. The sand grains keep the fissures open to release the gas or oil molecules which are collected in the pipe during the final stage of the fracking process.
Hydraulic fracking is more commonly referred to as hydraulic fracturing, hydrofracking or simply fracking. Slickwater used in the process, consists of 90% water, 9.5% sand and 0.5% chemical additives. The additives mainly help to reduce friction, keep the sand suspended and prevent pipe corrosion. However, many of the chemicals used are toxic, raising concerns about the potential contamination of groundwater, especially because this type of fracking uses more water than earlier fracturing methods.
Fracking and earthquakes
The safety of fracking has been questioned on several levels. In addition to claims that it contaminates the area around the wells, some have also made links between fracking and earthquakes. Research suggests that fracking could cause tremors both while pumping slickwater into the rock and when disposing of wastewater through underground injection. US States with active fracking wells have seen dramatic increases in seismic activity.
Natural gas fracking
The United States is the world’s largest producer of natural gas. Production has soared in the last 15 years because of fracking. Natural gas fracking now makes up about two-thirds of the US’ total gas output. It is often referred to as the “bridge fuel” that will aid the transition from coal to renewable energy sources such as wind and solar. Natural gas fracking has increasingly been seen as damaging to the environment and has been banned in several countries and some US states.
Much like natural gas fracking, oil fracking is on the rise in some countries while it’s banned in others. In 2014, US oil output saw its biggest rise in more than a century, putting it in third place among the largest oil producing countries. Oil production in Canada and Brazil has also reached record levels. However, the true cost of this economic boon remains unclear as more evidence emerges that the side effects of all types of fracking may ultimately outweigh its benefits.