Pros And Cons Of Hydraulic Fracturing

Hydraulic fracturing, commonly called fracking, is a drilling technique used for extracting oil or natural gas from deep underground.

Fracking is a hotly debated environmental and political issue. Advocates insist it is a safe and economical source of clean energy; critics, however, claim fracking can destroy drinking water supplies, pollute the air and contribute to the greenhouse gases that cause global warming.

How fracking works

Most fracking wells in use today rely on two technologies: hydraulic fracturing, which has been in use since the 1940s, and horizontal drilling, a technique that first became widespread in the 1990s.In simplified terms, the fracking process starts with a well that is drilled vertically or at an angle from the

But by 2010, that number had almost doubled to 510,000, according to the U.S. Department of Energy (DOE). And every year, about 13,000 new wells are drilled. According to a 2014 a study, at least 15.3 million Americans have lived within a mile of a fracking well that has been drilled since 2000.

The areas where fracking is most profitable include the Great Plains from Canada south into Texas, the Great Lakes region and an area known as the Marcellus Shale, which reaches from central New York into Ohio and south to Virginia, according to the U.S. Energy Information Administration (EIA).

The Marcellus Shale region is particularly attractive to gas drillers because it's a rich supply of natural gas — some call it "the Saudi Arabia of natural gas" or "Frackistan" — and because many of the region's rural communities are economically depressed and eager to attract an energy industry that enjoys handsome profits.

How safe is fracking?

Proponents of fracking claim that the drilling technique is a safe and clean method of securing essential sources of power that will meet U.S. energy needs for

Fracking is believed to be the cause of Oklahoma's strongest recorded quake in 2011 and more than 180 tremors in Texas between 2008 and 2009. To start off 2015, an area of North Texas had nine confirmed earthquakes in a 24-hour period. Fracking is being investigated as the cause.

According to a 2000 study of the Orito Field in Colombia, only around 15 percent of proppants can be removed after the fracking is done. Does leaving these foreign substances in a place where they weren't originally harmful? "No, there are no long- or short-term problems with leaving frack proppants in the fractures (fissures)," Rick Chamberlain, managing director the Berkeley Research Group, told Live Science.

Bjornerud agrees, "Even with the sand propping open the cracks, the weight of the overlying rock will, over months and years, cause the cracks to close and the rock’s permeability return to about what it was before the fracking." According to Bjornerud, this is a problem for oil and gas production since the process has to be done quickly, soon after the fracking fluids have opened up micro-cracks, or the amount of oil and gas that can be extracted rapidly decreases as the cracks progressively