Methane emissions from vast oil and gas operations in the densely populated Barnett Shale region of Texas are 50 percent higher than estimates based on the Environmental Protection Agency’s (EPA) greenhouse gas inventory, according to a series of 11 new papers published today in Environmental Science & Technology.
The majority of these emissions are from a small but widespread number of sources across the region’s oil and gas supply chain. These emissions come from the sort of leaks and equipment malfunctions that are relatively easy to prevent with proper and frequent monitoring and repair practices.
The sprawling Barnett region, fanning out westward from the cities of Dallas and Fort Worth, contains about 30,000 oil and gas wells, 275 compressor stations, and 40 processing plants. It is one of the country’s largest production areas, responsible for 7 percent of total U.S. natural gas output.
Unpredictable, Widespread Sources Dominate
A finding from the research shows that at any given time, roughly 75 percent of the methane emissions from production sites in the Barnett Shale tend to come from a set of elusive and dispersed sources. Higher emissions from these sites are often a result of avoidable operating conditions such as equipment leaks and tank venting that are relatively easy to prevent with frequent monitoring and repair practices.
The studies were coordinated by EDF as part of a larger effort to better understand where oil and gas methane emissions are coming from and how best to reduce them. The new findings are consistent with previous scientific work that indicates industry has a significant methane pollution problem driven by widespread, often unpredictable emission sources.
To better classify these emitters, researchers offer a new definition, calling them “functional super-emitters,” or those sites with the highest proportional loss rates (site-specific methane emissions relative to its production/volume of gas handled).
Simple Solutions for Reducing the Leaks
Routine leak monitoring is essential because these sources are difficult to anticipate – the leaks can emerge from a diversity of locations, at any point in time, jumping from site to site.
The good news is that there are many cost-effective ways to find and fix high-emitting sources. In fact, a 2014 report by ICF International found that by adopting already available technologies and operating practices, industry could cut methane emissions by 40 percent over five years for just one penny per thousand cubic feet of produced gas.
The bad news is, as easy and affordable as these solutions are, many companies simply are not using them. As long as they remain optional, it’s likely to stay that way.
Some states, like Colorado, have already begun directly regulating methane emissions from oil and gas operations and requiring comprehensive, frequent leak detection and repair. And in January, the White House announced plans to reduce methane emissions from the natural gas supply chain by 40 to 45 percent over the next ten years.
Details of the new plan are still in the works. In the coming weeks, EPA and the Bureau of Land Management (BLM) are both expected to propose rules to help meet the White House’s reduction goal. Based on the latest scientific research, including the papers released today, it’s important that these policies require both thorough and routine monitoring and maintenance to find and fix methane leaks.
Frequency is critical — the ICF report, for example, found that monthly inspections resulted in reducing emissions by 80 percent, while annual inspections reduced emissions by less than half.
Getting the Full Picture
The series of 11 papers represent the first findings of one of the largest and most comprehensive research campaigns on methane emissions in the oil and gas supply chain and will be followed by a paper fully synthesizing all of the researchers’ findings.
The work included 12 research teams from 20 universities and private research firms, including Colorado State University, Duke University, the National Oceanic and Atmospheric Administration and University of Colorado-Boulder, Pennsylvania State University, Princeton University, Purdue University, University of California-Davis and Scientific Aviation, University of California-Irvine, University of Cincinnati, University of Houston, University of Michigan, University of Texas-Dallas, Washington State University, West Virginia University, Aerodyne Research, Carbon Now Cast, Conestoga-Rovers & Associates, Picarro and Sander Geophysics.
The results of these papers tell us that we have a problem, but we already know there are cost-effective technologies and practices available to reduce emissions and make a big dent in waste and pollution.
By Steven Hamburg
Originally Published on July 7, 2015
The Energy Exchange Blog is a forum where EDF‘s energy experts discuss how to accelerate the transition to a clean, low-carbon energy economy. Follow them on Twitter here: @EDFEnergyEX
Methane photo courtesy of Shutterstock.
