Jun 17, 2014

Study finds supposedly plugged oil and gas wells in Pennsylvania are leaking a lot of methane

The Rural Blog: Abandoned oil and gas wells in Pennsylvania are creating significant amounts of methane, a potent greenhouse gas, according to a study by Princeton University. The study found that between 200,000 and 970,000 abandoned wells in the northern part of the state likely accounted "for 4 to 7 percent of estimated man-made methane emissions in that jurisdiction, a source previously not accounted for," Andrew Nikiforuk reports for The Tyee, a British Columbia publication. The study found "that leaks from abandoned oil and gas wellbores pose not only a risk to groundwater but represent a growing threat to the climate." 

An Associated Press investigation published in January found that Pennsylvania is one of four states where it was confirmed that oil and gas drilling has led to water pollution. Since 2005, the state has had 106 water-well contamination cases and in 2013 received 398 complaints that drilling polluted or otherwise affected private water wells. 

And it seems that complianants have few friendly ears to bend. Areport released in early 2013 by the Public Accountability Initiative found that many of Pennsylvania's policymakers, regulators and enforcement workers came from the oil and gas industry they oversee, or left state jobs for industry jobs. The report also found that Pennsylvania's last four governors and 45 current or state officials had ties to the gas industry. There is no direct federal regulation of oil and gas production except on federal land. (Read more)

For the Princeton study, researchers measured methane emissions from 19 abandoned wells, finding that "the highest-polluting well seeped 3.2 cubic metres of gas a day, or 1,168 cubic metres of gas a year. That's nearly $300 worth of natural gas annually," Nikiforuk writes. 

The study also found that "methane leaks from plugged wells, which were properly sealed with cement at the time of their abandonment, were just as high as rates from unplugged wells," Nikiforuk writes. "Wells connected to sandstone formations leaked more often than wells constructed in other formations." Researchers also "found ethane, propane and n-butane mixed with the methane—all indicators that the gas came from zones targeted by industry as opposed to swamps or natural sources," and methane leaks were more prevalent during the summer.