The Near-Term Mitigation Opportunity of Super-Emitters - A Case Study in the Permian Basin

Highlights 

Between April 30 – May 17, 2024, Carbon Mapper conducted a 13-day airborne campaign over a specific portion of the Permian Basin representing 98% of New Mexico oil and gas production. The team collected over 200,000 observations of oil and gas facilities and pieces of infrastructure and found the following:

• Overall, the Carbon Mapper team identified over 1,380 methane plumes in the surveyed region.
• Preliminary analysis shows that these plumes can be attributed to about 529 unique facilities. This data is publicly available on the Carbon Mapper data portal. 
• By quantifying these plumes, Carbon Mapper found that most leaks ranged between 50-500 kg/hr and many of them meet the super-emitter threshold defined by the EPA (100kg/hr or greater).
• Comparing these super-emitting sources to total emissions derived during the same time period from the TROPOMI satellite for this same portion of the Permian showed that they likely made up 55-60% of total emissions from that area.
• When we compared these results to airborne survey data dating back to 2019, we found that 19 of these facilities were ultra-persistent super-emitters. Together, over five years, these facilities lost enough gas into the atmosphere to match the emissions from 1.7 million passenger vehicles. 

Methane super-emitters identified in this campaign and others represent a disproportionate climate risk and opportunity — contributing a significant portion of a region's total emissions in some sectors in the short-term or for years at a time. This survey adds to the robust and growing body of observational data and insights Carbon Mapper makes publicly available to better understand and address methane super-emitters in key regions.  

Background — Remote Sensing Brings New Visibility and Insights to Methane on Multiple Levels 

Addressing methane emissions from oil and gas is crucial to securing climate, economic, and human health. This sector is responsible for about 23% of global human-caused methane emissions which come from equipment malfunctions, leaks, flaring, venting, and process emissions. They can be small and spread over wide areas, or large and concentrated to specific facilities or pieces of equipment. Identifying exactly where these emissions come from and which types of sources are contributing to regional emissions is important because it influences how they can be quantified, tracked, and ultimately mitigated.  

A growing number of remote sensing technologies including emissions-sensing aircraft and satellites are bringing new transparency to methane in different and complementary ways. For example, the European Space Agency’s TROPOMI satellite images much of the Earth’s land area daily, providing a frequent snapshot. But, with a high detection threshold it cannot see certain emissions nor can it attribute them to specific sources. MethaneSAT by the Environmental Defense Fund is optimized to detect, in aggregate, the myriad of small methane emissions over a wide area and can quantify the total emissions originating from a wide region or basin. The Carbon Mapper Coalition’s Tanager-1 satellite, built and operated by Planet Labs with technology from NASA’s Jet Propulsion Lab, is designed to zoom in further, detecting and quantifying emissions from facilities or pieces of equipment releasing high volumes of methane, and attributing these emissions to their specific source within 50 meters. These technologies and many others are providing valuable insights that can help society address all emissions in different ways and on different time scales. 

Within this ecosystem, Carbon Mapper focuses on detecting, quantifying, and acting on super-emitters. The United States Environmental Protection Agency (EPA) has defined super-emitters as any emission event for any duration that exceeds 100 kg/hr. At any moment in an oil and gas basin, the fraction of super-emitting infrastructure is small relative to all infrastructure but these sources can have a disproportionate impact on regional methane emissions. Super-emissions may be due to both known and planned operators (e.g., process venting) or due to equipment malfunction (e.g., pipeline leaks, unlit flares). 

The Super-Emitter Opportunity 

Years of direct observations by aircraft and satellite combined with robust scientific insights have shown us that super-emitters present a significant near-term opportunity to tackle oil and gas emissions for several reasons: 

1. Increased transparency is helping us better understand super-emitters. Building upon existing insights, Carbon Mapper fills a unique observational gap and provides publicly accessible, facility scale data that advances scientific understanding of these sources. For example, it was previously assumed that super-emitters were only short-lived events. However, our observations have shown that some can be very persistent — releasing methane into the atmosphere for years on end. This intelligence can help decision makers design more effective and efficient mitigation solutions. 
2. In some cases, a large share of a basin’s total emissions can be isolated to a select number of super-emitters. Mitigating emissions at these specific facilities can have a major and immediate impact to lower emissions across an entire basin or a company’s portfolio.
3. Oil and gas super-emitters have proven mitigation pathways. Especially in the U.S., there is a growing body of evidence (in California and Colorado for example) that once super-emitters are detected and operators are notified, many of these issues can be fixed with existing, cost-effective technologies or process improvements. These solutions are proven to reduce emissions as well as prevent product loss and increase profitability. 

Permian Overflights Find Significant Super-Emitter Activity

Carbon Mapper’s most recent overflights of the Permian Basin offer a compelling picture of the super-emitter opportunity. 

Between April 30 – May 17, 2024, Carbon Mapper conducted a 13-day airborne campaign over a section of the Permian Basin using the Arizona State University Center for Global Discovery and Conservation Science Global Airborne Observatory (GAO), an imaging spectrometer that is highly sensitive to high emissions sources of methane. During this period, we performed wall-to-wall mapping via multiple dates and overpasses of a region that represented 98% of New Mexico Permian oil and gas production. We collected over 200,000 observations of oil and gas facilities and pieces of infrastructure that included thousands of upstream well-sites, midstream compressors stations, gas processing plants, and hundreds of kilometers of pipeline infrastructure.

Overall, the Carbon Mapper team identified over 1,380 methane plumes in a specific portion of the New Mexico and Texas Delaware and Midland Basins. Preliminary analysis shows that these plumes can be attributed to about 529 unique facilities. This data is publicly available on the Carbon Mapper data portal. 

By quantifying these plumes, Carbon Mapper found that most leaks ranged between 50-500 kg/hr and many of them can be classified as high emissions sources or meet the super-emitter threshold defined by the EPA (100kg/hr or greater). Comparing these super-emitting sources to total emissions derived during the same time period from the area-flux mapping satellite TROPOMI for the same portion of the Permian showed that they likely made up 55-60% of total emissions from that area. These results are backed by Carbon Mapper’s robust methodology and externally validated controlled release experiments.

When we compared these results to airborne survey data dating back to 2019, we found that 19 of these facilities were ultra-persistent super-emitters. Ultra-persistent super-emitters are facilities or pieces of equipment that release high volumes of methane for weeks or months at a time. Carbon Mapper bases our classification of ultra-persistent super-emitters on multiple detections of super-emitter activity, a greater than 50% observed frequency, and at least 10 total observations. Together, over five years, these facilities lost enough gas into the atmosphere to match the emissions from 1.7 million passenger vehicles. 

Survey Approach and Methodology 

For this campaign, Carbon Mapper performed extensive airborne surveys using the GAO aircraft between April 30-May 17, 2024 (13 flight days total). A map of surveyed areas is shown in Figure 1.

We broke the campaign into two survey modes:

1. A wide-area survey (Box 1; Figure 1) encompassed most of the production and infrastructure in the New Mexico Permian. This area was surveyed in its entirety at least one time during the campaign.
2. “Intensive” surveys (Boxes 2-3; Figure 1) encompassed high production areas where the aircraft could completely map a single box twice in a day.

Together, these surveys resulted in over 200,000 unique upstream well-level measurements, as well as thousands of measurements at midstream compressors stations, gas processing plants, and coverage of hundreds of kilometers of pipeline infrastructure. 

Quantifying Emissions

Each site-level measurement went through a detailed quality control procedure to detect and quantify methane plumes. The protocols are described in Carbon Mapper’s Plume Detection Quality Control Guide and summarized as follows:

Plumes are identified when there is an excess abundance of methane observed in airborne imagery (concentration maps) that are uncorrupted by false signals and that can be attributed (i.e., are explicitly connected) to oil and gas infrastructure. Any methane enhancement signals that are not spatially connected to infrastructure are not classified or quantified, therefore minimizing any uncertainty related to quantification from ephemeral/transient plume enhancements.

Figure 2 shows an example of a plume that was detected at an upstream hydraulic fracture production site, and how the raw concentration imagery is analyzed jointly with simultaneously acquired visible aerial imagery. After the plume is detected and its origin is identified (here the plume origin is marked at point “K”), the plume is segmented and emissions are quantified. All raw visible, concentration, and segmented plume imagery for this campaign are available at Carbon Mapper’s Public Data Portal. 

Once all 200,000 observations were put through this rigorous quality control process, the Carbon Mapper team identified over 1,380 methane plumes. The emissions ranged from 5.3 kg/hr to 3600 kg/hr, but most emissions were between 50-500 kg/hr and fell into the EPA’s definition of super-emitters.

Identifying Ultra-Persistent Super-Emitters

To get a better sense of emissions in the region over a longer period, Carbon Mapper compared the results from this 2024 survey to observations conducted over the same region over the past five years. With airborne surveys dating back to 2019, Carbon Mapper has accumulated a uniquely large dataset that allows us to characterize emissions sources over the long-term. 

We isolated a class of super-emitters - “ultra-persistent super-emitters” - where (1) we have detected super-emission above 100 kg/hr in every year of airborne observation, (2) where the detection frequency across all observations is greater than 50%, and (3) where there are at least 10 site observations total. 

Applying these criteria, we find 19 ultra-persistent super-emitters (Figure 5), whose combined average emission rate totals to 6100 +/- 1900 kg/hr. Taken over 5 years, this quantity of gas lost to the atmosphere is equivalent to emissions from energy usage of a million homes or 1.7 million passenger vehicles. 

Understanding why these sources are disproportionately emitting at high rates and taking action to reduce these emissions would have a significant near-term impact for methane mitigation. When operators can connect measurements and direct observational data to best management practices and equipment maintenance and repairs, they can unleash the power of remote sensing as a tool to successfully reduce methane emissions, and improve economic performance. 

Conclusions

Methane super-emitters identified in this campaign and others represent a disproportionate climate risk and opportunity — contributing a significant portion of a region's total emissions in some sectors in the short-term or for years at a time. This survey adds to the robust and growing body of observational data Carbon Mapper makes publicly available to better understand and address methane super-emitters in key regions.  

There is strong evidence that providing reliable data at this level of granularity can empower industry, policymakers, regulators, and civil society to take actions that reduce emissions at the source. Through years of regional demonstration pilots leveraging airborne surveys, Carbon Mapper found that nearly half of super-emitting events flagged for state agencies and operators were previously unknown, and once identified, were able to be mitigated.

While the Permian Basin is a prime example of the need for, and significance of, remote sensing with certain capabilities to drive awareness and action on super-emitters, it is just one region. The urgency exists to scale up, and quickly. 

Carbon Mapper is working with a coalition of partners and aims to grow a constellation of satellites to detect and track up to 90% of super-emitting sources globally with daily frequency or better. By scaling up observations, and continuing to make methane data publicly available, we can advance data transparency, strengthen awareness on the exact sources of emissions, improve accountability, prioritize solutions and investments, and help society reduce emissions quickly to meet bold climate goals.