Appalachian Basin’s methane emissions fall despite increase in gas production |
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Stephen Huba

Two new reports have put some wind in the sails of the oil and gas industry at a time when Pennsylvania is trying to tighten the rules on methane emissions.

The reports show a dramatic decline in methane emissions even as natural gas production has been on the increase.

“It does seem counterintuitive,” said Nicole Jacobs, team lead for Energy In Depth, a project of the Independent Petroleum Association of America.

Energy In Depth’s report said that, despite significant natural gas production increases in the Appalachian Basin between 2011-2017, methane emissions fell from 5.3 million metric tons to 4.7 million metric tons – resulting in an emissions intensity reduction of 82%.

What’s more, a national inventory by the U.S. Environmental Protection Agency showed that, in 2017, greenhouse gas emissions in general were at their lowest level in 25 years and methane emissions in particular are down 18.8% from 1990.

The measures are taken from existing unconventional well sites and are largely from company data that is self-reported.

Jacobs said the reasons for the decline are varied and have to do with increased efficiencies and improved technologies in the oil and gas industry.

“Several companies have come out and made very specific statements about reducing methane emissions on (unconventional well) sites,” she said. “Over the course of the last several years, companies have made a point to discuss some of the technology they’re using and to make a more public statements on reducing those emissions. The data shows they were already doing that – it’s just more of a concerted effort now.”

The primary component of natural gas, methane accounted for about 10.2% of all U.S. greenhouse gas emissions from human activities in 2017, according to the EPA.

Methane emissions are the target of a draft plan, announced by the state Department of Environmental Protection in December, to reduce leaks from the state’s oil and gas wells and improve leak detection. The plan, which would exempt most conventional gas wells, conforms to a 2016 Obama-era rule that requires certain states to impose new emissions controls for oil and gas field sources by early 2021.

Pennsylvania, the nation’s No. 2 natural gas producer, has an estimated 80,000 conventional oil and gas wells and about 10,651 active unconventional gas wells, according to DEP.

DEP’s proposal would impose stronger limits on pollutants known as volatile organic compounds, or VOCs, while at the same time reducing methane emissions.

In light of the Trump administration’s desire to withdraw the 2016 rule, the Marcellus Shale Coalition, an oil-and-gas trade group, has asked the DEP to delay imposition of the methane emission regulations.

“We do … have concerns about potential costs, as well as DEP’s timing given ongoing federal regulatory activity associated with existing source emissions,” said coalition President David Spigelmyer.

Spigelmyer said the oil and gas industry is already identifying and implementing new technologies and procedures designed to reduce methane emissions.

“Since methane is the very product that our members market and sell, operators have every incentive to minimize losses (due to leaks),” said James Welty, coalition vice president for government affairs.

Some of those improvements include:

  • Eliminating venting and flaring by directing the gas that flows back during well completion activities directly into pipelines.
  • Using vapor recovery systems to collect vapors from dehydrators, water trucks and tanks.
  • Using air instead of gas for pumps and pneumatic controllers.
  • Employing leak detection and repair equipment on a recurring basis to identify and eliminate leaks.

The Environmental Defense Fund, however, criticized the recent reports as underestimating the amount of methane emissions coming from unconventional wells. The EDF said the reports rely too heavily on self-reported data and miss other potential sources of emissions.

EDF scientist David Lyon said trends also are hard to track because the relevant data was not available back in the 1990s.

“We absolutely know that the current emissions are very high. … Regardless of whether they’ve gone up or down, there’s many things they can do to get them to go down in the future,” Lyon said.

A 2018 analysis by EDF estimated that Pennsylvania’s oil and gas operators emit more than 520,000 tons of methane a year, primarily from leaky, outdated and malfunctioning equipment.

EDF used a 2015 study with 35 site-level measurements to estimate Pennsylvania emissions – results reinforced by a new study that relied on a dataset of 673 Pennsylvania well pads, Lyon said.

“Compared to other regions, Pennsylvania unconventional wells have lower loss rates, but since the wells have very high production, this leads to high absolute emissions,” he said, noting that loss rates are from 0.45% to 0.64%.

Jacobs said such leakage rates are well within acceptable thresholds. In order for natural gas to be considered a clean fuel, the leakage rate has to stay under 3.2%, she said.

Calling the EDF analysis an agenda-driven “activist report,” Spigelmyer praised oil and gas operators for their efforts at reducing methane emissions.

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