New Study Measures Methane Emissions from Natural Gas Production and Offers Insights into Two Large Sources

Researchers find a small percentage of wells accounts for the majority of emissions.


AUSTIN, Texas — A team of researchers from the Cockrell School of Engineering at The University of Texas at Austin and environmental testing firm URS reports that a small subset of natural gas wells are responsible for the majority of methane emissions from two major sources — liquid unloadings and pneumatic controller equipment — at natural gas production sites.

With natural gas production in the United States expected to continue to increase during the next few decades, there is a need for a better understanding of methane emissions during natural gas production. The study team believes this research, published Dec. 9 in Environmental Science & Technology, will help to provide a clearer picture of methane emissions from natural gas production sites.

The UT Austin-led field study closely examined two major sources of methane emissions — liquid unloadings and pneumatic controller equipment — at well pad sites across the United States. Researchers found that 19 percent of the pneumatic devices accounted for 95 percent of the emissions from pneumatic devices, and 20 percent of the wells with unloading emissions that vent to the atmosphere accounted for 65 percent to 83 percent of those emissions.

“To put this in perspective, over the past several decades, 10 percent of the cars on the road have been responsible for the majority of automotive exhaust pollution,” said David Allen, chemical engineering professor at the Cockrell School and principal investigator for the study. “Similarly, a small group of sources within these two categories are responsible for the vast majority of pneumatic and unloading emissions at natural gas production sites.”

Additionally, for pneumatic devices, the study confirmed regional differences in methane emissions first reported by the study team in 2013. The researchers found that methane emissions from pneumatic devices were highest in the Gulf Coast and lowest in the Rocky Mountains.

Continue reading...

Liquid unloadings and plunger lift operations in natural gas production (Animations will open in new tabs)

liquids unloading

A liquid unloading is one method used to clear wells of accumulated liquids to increase natural gas production.

plunger lift scenarios

A plunger lift operation is one type of liquid unloading mechanism.

Dave Allen

Principal Investigator

Dr. David Allen is
the Gertz Regents Professor of Chemical Engineering, and the Director of the Center for Energy and Environmental Resources, at The University of Texas at Austin.

Read more »

Additional Resources

Presentations of study (overviews):

Study FAQs, for pneumatic controllers and liquid unloadings, organized into three sections: methods and results; comparing this work to other studies; and interpreting the results

Study website, Center for Energy and Environmental Resources

Study disclosures

ceer logo

Media Contacts

Sandra Zaragoza, Media Relations Manager, Cockrell School of Engineering,, 512-471-2129 (o), 830-734-7510 (c)

J.B. Bird, Director of University Media Outreach, The University of Texas at Austin,, 512-471-4550 (o), 512-750-3512 (c)

For additional press contacts, visit the study website.