The Facts Behind the Frack: Scientists Weigh in on the Hydraulic Fracturing Debate
Ehrenberg, Rachel, Science News
To call it a fractious debate is an understatement.
Hydraulic fracturing, or fracking, wrenches open rock deep beneath the Earth's surface, freeing the natural gas that's trapped inside. Proponents argue that fracking-related gas recovery is a game changer, a bridge to the renewable energy landscape of the future. The gas, primarily methane, is cheap and relatively clean. Because America is brimful of the stuff, harvesting the fuel via fracking could provide the country jobs and reduce its dependence on foreign sources of energy.
But along with these promises have come alarming local incidents and national reports of blowouts, contamination and earthquakes. Fracking opponents contend that the process poisons air and drinking water and may make people sick. What's more, they argue, fracking leaks methane, a potent greenhouse gas that can blow up homes, worries highlighted in the controversial 2010 documentary Oasland.
Fears that fracking companies are operating in a Wild West environment with little regulation have prompted political action. In June, the group Don't Frack Ohio led thousands of protesters on a march to the statehouse, where they declared their commitment to halting hydraulic fracturing in the state. Legislation banning the process has been considered but is now on hold in California. New York--which sits atop a giant natural gas reserve--has a statewide fracking moratorium; pending policies would allow the process only where local officials support it.
Despite all this activity, not much of the fracking debate has brought scientific evidence into the fold. Yet scientists have been studying the risks posed by fracking operations. Research suggests methane leaks do happen. The millions of gallons of chemical-laden water used to fracture shale deep in the ground has spoiled land and waterways. There's also evidence linking natural gas recovery to earthquakes, but this problem seems to stem primarily from wastewater disposal rather than the fracturing process itself.
While the dangers are real, most problems linked to fracking so far are not specific to the technology but come with many large-scale energy operations employing poor practices with little oversight, scientists contend. Whether the energy payoff can come with an acceptable level of risk remains an open question.
"People want it to be simple on both sides of the ledger, and it's not simple," says environmental scientist Robert Jackson of Duke University. "Our goal is to highlight the problems, so we can understand the problems and do what we can to help."
What is hydraulic fracturing?
Hydraulic fracturing has been cranking up output from gas and other wells for more than 50 years. But not until fracking joined up with another existing technology, horizontal drilling, was the approach used to unlock vast stores of previously inaccessible natural gas. The real fracking boom has kicked off in just the last decade.
Conventionally drilled wells tap easy-to-get-at pockets of natural gas. Such gas heats homes and offices, fuels vehicles and generates electricity. But as easily accessible reserves have been used up, countries seeking a steady supply of domestic energy have turned to natural gas buried in difficult-to-reach places, such as deep layers of shale.
Gas doesn't flow easily through shale or other impermeable rock. Drilling a conventional well into such formations would gather gas only from a small area right around the well. And, for shale in particular, many formations in the United States extend hundreds of kilometers across but are less than 100 meters thick, hardly worth sending a vertical well into.
Combining hydraulic fracturing with horizontal drilling offers a way to wrest gas from these untapped reserves. By drilling sideways into a rock formation and then sending cracks sprawling though the rock, methane can burble into a well from a much larger area. …