Small Gas Wells Responsible for Half of Methane Emissions

Low-producing oil and gas wells are responsible for a disproportionate amount of methane emissions, a recent study determined. The study by the Environmental Defense Fund, which was recently published in the journal Nature Communications, found that 80 percent of more than 800,000 U.S. oil and gas well sites are low producers, averaging 15 barrels or less of oil or gas equivalent per day. While those wells produced just 6 percent of the country’s oil and gas, they emit half of the industry’s methane emissions. Methane is a potent climate-warming greenhouse gas with 80 times the warming potential of carbon dioxide over a 20-year period. The study concluded that these wells emit methane at a rate 6 to 12 times higher than the national average – allowing approximately 10 percent of their gas to leak directly into the atmosphere. That translates to roughly 4 million metric tons of methane emissions annually. “The methane footprint of these small wells is enormous and can’t be ignored,” said Mark Omara, EDF scientist and lead author of the study, in a press release. “Our research shows that the total methane emitted from the country’s half-million low-producing wells has the same impact on the climate every year as 88 coal-fired power plants.” The study pointed out that many of these small wells, which are mostly conventional, are exempted from environmental regulations and regular monitoring requirements, The Environmental Protection Agency is proposing new rules to reduce methane emissions from new and existing wells but they would exempt sites from monitoring if they are expected to release less than three tons of methane per year. In addition, Pennsylvania is finalizing regulations to limit methane and volatile organic compound emissions from existing wells, but low-producing wells again are excluded. Many of the state’s operators are small, conventional drillers, and industry groups argue they would be driven out of business by requiring more monitoring and regulation. Three trade groups, including Pennsylvania Independent Oil & Gas Association, recently filed a lawsuit asking to block the publication of the rule because a 2016 law requires conventional wells to be regulated separately from unconventional wells. According to the EDF study, much of the emissions from marginal wells are the result of maintenance and mechanical issues and could be avoided with additional site inspections and oversight. EDF argues that the additional monitoring could pay for itself by preventing valuable methane from leaking into the atmosphere instead of being sold by the producer. Many large gas producers are recognizing the need for methane emission reduction and taking voluntary steps to do so through state-of-the-art monitoring technology and equipment.