All About Fracking
This method of natural gas mining has come under close scrutiny from shock-doc filmmakers. Do the facts match the hype?
A lot of natural gas mining is easy; you drill a hole, the gas comes right up. But once you get down deep enough, between around 1.5 and 6 kilometers deep, the pressure is so high and the rocks are so tight that the gas can't move to your borehole.
The standard solution to this is hydraulic fracturing, or fracking. Water is pumped down into the deep shale at really high pressure, just like a hydraulic ram, and splits open the fissures. Then sand is mixed with the water, and gets distributed throughout the cracks to prop them open. The water is pumped back out, and now the gas can freely flow to the borehole.
The controversy comes mainly from the fact that about 1/2 of 1% of the fluid consists of lubricants and surfactants, needed to get the sand through the system and into the fissures. Opponents believe that these agents can poison groundwater supplies, or even worse.
The most dramatic criticism of fracking was this scene from the 2010 shock-doc Gasland, by avant-garde stage director Josh Fox. It showed a family whose tap water was actually flammable, and Fox blamed the fact that fracking was used in the area.
An investigation into this family's well, which was ignored by the movie, discovered that their well had been drilled directly into a shallow natural gas deposit. This is common and not a problem if the well is properly vented. Theirs wasn't, so gas got into their water.
How do we know it had nothing to do with fracking? Water wells range in depth from a few meters to a few hundred at the very deepest, but fracking takes place kilometers deeper, past numerous layers of bedrock. Years of study have proven what geologists have always known: there's just too much distance of solid rock between the two regions for any seepage to take place. Since the fracking fluid is removed right after the sand is inserted, there isn't even any fluid there that might seep.
Instead, it's best to understand the real concerns with fracking. These include surface spills, just like we have with maple syrup trucks or gasoline trucks; and of course the disposal of the fracking fluid, usually done into ultra-deep wells.
Just remember: whenever you hear non-experts claim to have discovered something shocking and sensational unknown to science, you have very good reason to be skeptical.
— Brian Dunning
References & Further Reading
Admin. "Debunking Gasland." Energy in Depth. Energy in Depth, 9 Jun. 2010. Web. 4 Sep. 2011. <http://www.energyindepth.org/2010/06/debunking-gasland/>
Department of Environmental Protection. Methane Gas and Your Water Well. Philadelphia: Commonwealth of Pennsylvania, 2009.
DOE. Modern Shale Gas Development in the United States: A Primer. Washington, DC: U.S. Department of Energy, 2009.
Editors. "The Facts About Fracking." The Wall Street Journal. 25 Jun. 2011, Newspaper.
Fischetti, M. "The Drillers Are Coming: Debate over Hydraulic Fracturing Heats Up." Scientific American. 12 Jul. 2010, Volume 303, Number 1.
Fox, J. "Gasland: A Film by Josh Fox." http://www.gaslandthemovie.com/. International WOW Company, 17 Dec. 2009. Web. 3 Aug. 2011. <http://www.gaslandthemovie.com/>
Maitland, G., Shipton, Z., Bradshaw, M., Fisher, Q., Taylor, K. "Got a question about fracking? Get it answered by an expert." Live Energy Q&A. Sense about Science, 12 May 2015. Web. 7 Sep. 2015. <http://www.senseaboutscience.org/pages/fracking-q-and-a.html>
Osborn, S., Vengosh, A., Warner, N., Jackson, R. "Methane contamination of drinking water accompanying gas-well drilling and hydraulic fracturing." Proceedings of the National Academy of Sciences. 9 May 2011, Volume 108, Number 20: 8172-8176.
Puko, T. "Fracking ruled out as contributor to East Coast quake." Pittsburgh Tribune-Review. 6 Sep. 2011, Newspaper.
Saba, T., Orzechowski, M. "Lack of data to support a relationship between methane contamination of drinking water wells and hydraulic fracturing." Proceedings of the National Academy of Sciences. 9 May 2011, Volume 108, Number 20: 8177.
Stelle, E. "Gasland Debunked." Commonwealth Foundation. Commonwealth Foundation for Public Policy Alternatives, Inc., 21 Jun. 2010. Web. 9 Sep. 2011. <http://www.commonwealthfoundation.org/policyblog/detail/gasland-debunked>