Scientists Track Down Serious Methane Leaks In Natural Gas Wells
STEVE INSKEEP, HOST:
Scientists are looking for ways for fracking to be less damaging. New fracking technology hass produced a natural gas boom, but it also poses a specific environmental problem. There are more gas leaks from wells, and it's hard to find out where the worst of those leaks are coming from. NPR's Christopher Joyce reports on a study out today with some answers.
CHRISTOPHER JOYCE, BYLINE: Hydraulic fracturing created this gas boom. The technique fractures rock deep underground that releases gas. It's mostly methane that comes up through a well to a concrete drilling pad. And that pad is one place where you get leaks. Leaks are bad because methane is a powerful greenhouse gas. It warms the atmosphere. Dave Allen wants to stop these leaks.
DAVE ALLEN: We should know what our options are for reducing emissions from those things that are already in place at a minimum. We need information.
JOYCE: Allen is a chemical engineer at the University of Texas. His team has visited over 100 wells. And what he's found is similar to how pollution is created on the highways, where a relatively few clunkers cause most of the problem.
ALLEN: So similar sort of distribution here. A small fraction of the sources are giving you the majority of emissions.
JOYCE: One source is a common device called a pneumatic controller. It uses natural gas to open and shut valves in the equipment in pipelines. One-fifth of the devices the team examined emitted almost all the leaked methane. They found similar results for another widely used practice, liquid unloading. Rising gas carries liquid with it that can plug up the well. When workers remove the liquid, gas escapes into the air, sometimes tens of thousands of cubic feet of gas.
ROBERT JACKSON: The typical home uses about 200 cubic feet of natural gas in a day.
JOYCE: Robert Jackson is an environmental scientist at Stanford University who tracks methane.
JACKSON: A single unloading is about the same as a couple hundred houses worth of gas.
JOYCE: The federal Environmental Protection Agency estimates leak rates from company reports. The Texas team's measurements found some rates to be higher than EPA's figures. Jackson, who's not part of the team, says the research looks solid. But, he adds, that it only surveyed a small cross-section of the nation's wells, and gas company crews knew when their wells were going to be tested.
JACKSON: You're not getting access to wells across the country necessarily. And also, if companies are getting early warning, if you will, of when you're going to visit, then perhaps they're a little more careful.
JOYCE: Some environmental groups have criticized the University of Texas project because gas companies help pay for it. Team leader Dave Allen replies that independent scientists reviewed their research, which appears in a journal, Environmental Science and Technology. The Environmental Defense Fund also underwrites the project. EDF's Vice President Mark Brownstein says it's revealed a serious problem.
MARK BROWNSTEIN: You can't manage what you don't measure. And the industry has gotten complacent about environmental performance.
JOYCE: The Texas team says if most leaks are from just a few sources, it should be easier to find them. But Brownstein says that won't happen by itself.
BROWNSTEIN: The study certainly points to the importance of having a policy where all oil and gas operators are required on a regular basis to survey their sites.
JOYCE: A few states do require regular surveys, and the federal government has proposed rules to get better information as well. Christopher Joyce, NPR News.