Fracking has raised alarms around the country. A moratorium on the practice, injecting water to shatter rock and reach once inaccessible pockets of gas, is in effect in New York state. Critics say the technique poses unacceptable health and environmental risks for nearby communities.
Yet fracking is not going away—the opposite in fact. An estimated 130,000 new shale gas wells have been sunk over the last decade, about 35 a day, while the total number soared more than 50% to about 510,000 in 2010, reports USA Today.
It’s possible, however, that fracking, if practiced responsibly, isn’t the menace it has appeared. The practice of shattering rock to reach hydrocarbons has been around since the 1940s, and was first applied to shale deposits (PDF) in the 1970s and 1980s. Disastrous cases of drinking water contamination have occurred, often by irresponsible drillers. There is also an ongoing effort by environmental groups to see fracking balanced against our need for energy (see an agreement on new voluntary standards).
Most of this argument is over water, reports the Financial Times. Hydraulic fracturing uses between 4 and 6 million gallons of water for each well, says the National Petroleum Council, an industry representatives and environmental advisory group. When water comes back up, it’s full of gas—and contaminants that must be processed or stored. "It’s becoming critical to the entire U.S. strategy to do something about this water," says Riggs Eckelberry, the chief executive of OriginOil, a company treating water for the oil and gas industry, in the FT.
One of the strategies is to do away with the water all together. A technique of pumping pressurized carbon dioxide (CO2) into wells to shatter the rock and push out more oil and gas is gaining steam. Researchers in Japan, publishing in Geophysical Research Letters, showed injecting super-critical CO2 into granite blocks creates more extensive fracture patterns and theoretically outperforms conventional water-based techniques.
Eliminating the need to truck, pump and process millions of gallons of water, compared to CO2 is a major benefit. But the most promising, if still uncertain, advantage is using shale formations for carbon dioxide storage, potentially removing a major source of warming greenhouse gas emissions (GHG) to the atmosphere while extracting cleaner energy than today’s coal mines. The Department of Energy estimates shale formations could be the second largest geologic GHG storage option for the U.S. after underground saline reservoirs, capable of holding 45 gigatonnes.
Wyoming has already started using carbon dioxide in its wells, and it could become economical in other places with CO2 pipelines—originally built for conventional fossil fuel extraction, says Robert Dilmore, a research engineer at the U.S. National Energy Technology Laboratory, in the MIT Technology Review.
But it’s not without costs. Carbon dioxide from wells must be separated out from the natural gas, and CO2 pipelines— 3,900 miles of the infrastructure already exists—will never reach every well. Finally, the economics aren’t always a money maker. For CO2 to gain traction away from existing pipelines, either hydraulic fracking must cost more due to its risks or water scarcity, or the benefits of CO2 from carbon sequestration and lower pollution must be monetized.
Still, the potential to tap into cleaner burning energy while slashing carbon emitted into the atmosphere may change the equation for the future of fracking.
[Image: Drill, Lock the Gate Alliance via Flickr]