The U.S. Department of Energy’s (DOE) Office of Fossil Energy (FE) has approved an unsolicited proposal, titled Quantification of Methane Emissions from Marginal (Small Producing) Oil and Gas Wells, received from GSI Environmental Inc. (GSI).  The data collected from well sites in basins across the United States will help address critical knowledge gaps and support best management practices that are appropriate for marginal wells.

This effort complements related DOE research and analysis projects conducted by the National Energy Technology Laboratory (NETL) to improve understanding of methane emissions and identify potential reduction strategies that can improve the operational efficiency of the Nation’s natural gas production and delivery systems.

In June 2016, the U.S. Environmental Protection Agency (EPA) published a final rule in the Code of Federal Regulations to amend the New Source Performance Standards at subpart OOOO, and finalize new standards at subpart OOOOa to reduce methane emissions from new and modified oil and gas facilities. The updated standards included requirements for marginal well sources—oil wells that produce less than 15 barrels per day or gas wells that produce less than 90,000 cubic feet per day—which were not previously addressed.  

EPA’s decision was based on limited data. The Agency had presumed emissions from marginal and non-marginal well sites were comparable, but that conclusion was derived from data amassed from studies employing a wide variety of technical approaches, none of which were designed to assess emissions specifically from representative populations of marginal well sites.

As part of an ongoing regulatory review and reconsideration process, on September 11, 2018, EPA issued proposed targeted improvements to the 2016 standards that aim to streamline implementation, reduce duplicative EPA and state requirements, and decrease unnecessary burdens on domestic energy producers. The Agency continues to review other aspects of the 2016 rule that could be the subject of future rulemaking. 

While the costs of regulatory compliance impact all producers, small independent oil and gas producers who operate many of the over 700,000 marginal wells that dot the United States could be disproportionately impacted, with associated economic impacts to energy production, states, and communities.

Recognizing these challenges, GSI proposed to collect and evaluate representative, defensible, and repeatable data from each type of well (marginal vs. non-marginal, oil vs. natural gas). This data, together with data from existing sources, will be compiled, evaluated for usability and representativeness, and analyzed to answer two key questions:

• What conclusions can be reliably drawn regarding the relative methane emissions among significant marginal and non-marginal well site populations based on existing available information?
• What are the key gaps in understanding the relative frequency and magnitude of emissions from marginal vs. non-marginal well sites?

Once these questions are addressed, GSI will develop a focused and detailed scope of subsequent field investigations, as appropriate, to address critical data gaps. Study conclusions will also focus on identification and implementation of appropriate best management practices, so that the United States can continue to rely on traditional oil and natural gas resources for clean, secure, and affordable energy while enhancing environmental protection.