Critics of shale gas drilling frequently cite its numerous and drastic environmental risks to argue for tighter regulation. Fracking can cause mini-earthquakes that allow gas and chemicals to seep into groundwater. Above-ground spills of chemicals like benzene used in the process kill wildlife. And the truckloads of equipment required for drilling need roads that carve up the countryside and burn fossil fuels on the way.
The documentary Gasland, an Academy Award-nominated public-relations nightmare for the shale gas industry, put many of these arguments on film. New York filmmaker Josh Fox tours some of America’s most prolific shale gas sites, documenting claims that nearby wells have turned tap water into black sludge or – in several dramatic pieces of footage – made faucet water flammable.
Industry group Energy in Depth contested Fox’s claims, calling Gasland, “politics at its worst, art at its most contrived, and contradictions of fact found around every bend of the river.”
Though the industry has launched a counter campaign to convince the public that fracking is safe, popular opposition to shale gas drilling is mounting. New York state approved a temporary ban on drilling last year, and the EPA began a two-year investigation into environmental and health impacts.
Studies have also questioned the industry’s mantra that unconventional gas generates half the carbon emissions of coal. Cornell University Professor Robert Howarth argues that when the thousands of truckloads of equipment transport required for fracking each well are taken into account, shale gas exploitation may produce more greenhouse gas than oil drilling and possibly more than coal mining.
In China, however, the biggest environmental problem with shale gas exploration is the millions of gallons of fresh – not salt – water required to frack each well, only about one-third of which returns in brackish form to the surface. China has 22% of the world’s population but only 7% of its fresh water.
Jay Ewing, who oversees well completions for Devon Energy, said water is the industry’s biggest challenge. He said Devon has been recycling flow-back water and filtering out solids like chloride salts since 2005.
“The technology still has a long way to go to develop the ability to recycle all of our waste water that we produce. There’s a lot of trial and error going on, but it is not a simple technology that’s going to happen overnight.”
Faced with an environmental backlash, drilling companies in North America and Europe profess that more technological development is needed.
The CEO of oilfield services company Schlumberger admitted as much to investors last year: “Looking at shale gas in particular we are convinced that the brute force approach established in North America will not be practical overseas, either from a financial or an operational standpoint.”
Recent innovations have made extraction more sophisticated: 3D seismic imaging allows drillers to target reservoirs more accurately, for example.
Petrohawk is developing a “choke method” to lower initial production costs and extend the life of shale wells, while oifield services company GASFRAC has patented a “waterless frac” that uses liquefied petroleum gas as fracturing fluid.
But some analysts are skeptical. “I suspect if they were very successful, we would have heard about it by now,” said Bill Holland, editor of Platts’ Gas Daily.