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New Tech Can Reveal a Vast Network of Methane Leaks

But it is unclear if oil and gas companies and their regulators will respond

Natural gas, primarily methane, is burned at a Texas oil well.

Natural gas, primarily methane, is burned, or “flared,” into the atmosphere at a Texas oil well. 

Credit:

Nick Simonite

Paolo Wilczak banked his two-seat airplane above a grid of flat, industrial land in West Texas. About 60 meters below, I saw a bright flash of orange. It was a “flare”—a tall, vertical pipe beside a commercial oil well and storage tanks that was spitting flames into the windy afternoon air. The pipe was burning off unwanted gases, largely methane, that had risen from belowground with the oil. “Let’s see if this flare is doing its job,” Wilczak said, his voice barely audible above the plane’s loud single engine.

Wilczak is a 23-year-old pilot and researcher for Scientific Aviation, a Boulder, Colo., company that tracks air quality for clients such as the United Nations, government agencies, environmental groups and private companies. We were flying about 48 kilometers north of Odessa, a city in the heart of the Permian Basin, a Kansas-size expanse that straddles West Texas and southeastern New Mexico. Hundreds of millions of years ago this region was covered by a wide, shallow sea populated by tiny organisms that built vast reefs. The decomposing remains of those creatures collected in oil-forming deposits now as deep as 3,000 meters or more. Today the Permian is home to one of the world’s biggest oil fields—the largest and fastest-growing in the U.S., the source of 38 percent of the country’s oil and 17 percent of its natural gas. After the U.S. ban on oil exports was lifted in late 2015, oil and gas production here exploded. There are now some 150,000 active wells in the Permian; oil production is more than four times what it was a decade ago.

The Permian is also one of the country’s largest emitters of methane—a potent greenhouse gas that is increasingly being recognized as an important driver of the climate emergency. Since 2019 Scientific Aviation’s planes have been in high demand as scientists have tried to get a handle on the amount of greenhouse gases leaking from Permian oil tanks, processing plants and other infrastructure.

Wilczak eased the plane downward toward the flare and started to circle it in a tight spiral. Below us a circuit-board pattern of straight dirt roads and flat squares of bare soil stretched toward the horizon. Pumpjacks in the squares nodded up and down as they sucked up oil from inside the earth. As we looped around the column of atmosphere above the flare, tubes mounted under the right wing pulled air into a spectrometer behind our seats. The instrument analyzed the air samples and displayed green, red and blue graph lines on a laptop screen between us. The green line—carbon dioxide—spiked, but the blue line, for methane, remained low. The flare was burning cleanly, converting methane into less potent, though still problematic, carbon dioxide.

Many operators flare their gas, often because they are interested only in the oil. When flares work properly, they convert methane to carbon dioxide and water vapor while reducing the amount of volatile organic compounds released into the atmosphere, which can create smog and are linked to respiratory and cardiovascular problems. But flares can malfunction, pipelines can leak, and operators can vent methane without burning it to relieve pressure and prevent explosions. Other large sources include emissions from gas-powered controllers that open and shut valves on wellheads, tanks and other hardware. Last September, Wilczak recorded a leak so large it strained the spectrometer’s limits. “It was way higher than anything I had ever seen in my over 1,000 hours of taking measurements,” he told me later. An engine at a compressor station had failed, causing the plant to emit more than 12,000 kilograms of methane per hour—the global warming equivalent of driving 65 cars for a year. He made sure the operator was notified, and when he surveyed the area the next day, he found that the leak had been fixed.

Aging infrastructure compounds the problem. The Permian’s first boom dates to the early 1920s, when a small group of investors placed an improbable bet on an oil well called Santa Rita No. 1. When it came in as a gusher, it triggered a land rush that helped to build Texas’s legendary fossil-fuel industry. Many wells are decades old—far older than those in comparable fields, or plays, such as North Dakota’s Bakken and Texas’s Eagle Ford, where infrastructure is more reliable, says Artem Abramov, head of shale research at consulting company Rystad Energy. Hundreds of thousands of wells and pipeline sections have simply been abandoned, their decaying seals and fittings leaking methane that rises from belowground.

Since at least 2010, university scientists, energy companies and other experts, many brought together by the Environmental Defense Fund (EDF), have worked to understand the impact of new extraction techniques such as modern hydraulic fracturing, or fracking, and horizontal drilling on methane emissions. A major obstacle to this project has been the difficulty of finding individual emissions sources. Methane is colorless and odorless; it cannot be spotted with the naked eye. And before anyone can fix a leak, they have to locate it.

Recently the Permian has become a laboratory for scientists to experiment with new ways of identifying emissions. Much of the impetus came from new Environmental Protection Agency and state regulations, enacted beginning in 2015 that mandated tougher air emissions and monitoring requirements for oil and gas companies. Researchers are piloting planes, flying drones, directing satellites and installing complex ground-sensor networks. New satellites scheduled to launch soon will track methane at global and local scales, making data freely available to anyone.

There is a large gap, however, between measuring something and controlling it. New technology will have to be matched with stronger regulations and cooperation from a powerful oil and gas industry that prefers to police itself. ExxonMobil, BP and a few other major producers have pledged to cut their Permian emissions over the next two decades, but not all companies are making such promises, which are not binding anyway. A December 2020 survey by the Dallas Federal Reserve Bank found that only about one third of companies operating in the Permian had plans to reduce emissions or flaring. All of which is why people such as Robert Howarth, a biogeochemist and ecosystem scientist at Cornell University, argue that measuring methane emissions from individual sources and making that information public could be the best way to hold polluters to account.

West Texas and southeastern New Mexico have enormous oil and gas deposits, tapped at tens of thousands of sites (earthen squares). Credit: Nick Simonite

Land of Leaks

Methane comes from a vast array of natural and anthropogenic sources: wetlands, shallow lakes and rivers, livestock farming, landfills, agriculture, wastewater treatment plants. Daniel J. Jacob, an atmospheric chemistry professor at Harvard University, estimates that anthropogenic methane sources are evenly divided among oil and gas infrastructure, coal operations, landfills, livestock farming and agriculture.

It is much harder to control emissions from livestock than from a leaky oil well. Combine that fact with the rapid growth in fossil-fuel industries, and it is clear why they are the primary target in the push to control the greenhouse gas. Howarth says oil and gas are probably the largest and fastest-growing contributors; the post-2006 methane increase coincides with the U.S. fracking surge.

Methane accounts for only about 10 percent of U.S. greenhouse gas emissions, but it is much more powerful than carbon dioxide in trapping heat over a 10-year period. Atmospheric methane levels have risen relentlessly since 2007. This past April the National Oceanic and Atmospheric Administration reported that the one-year increase in methane concentrations for 2020 was an all-time high of 14.7 parts per billion, despite the economic slowdown caused by the coronavirus pandemic.

Permian basin was a shallow sea with extensive reefs hundreds of millions of years ago. Credit: Mapping Specialists

Yet stopping methane emissions from oil fields is relatively straightforward once they have been located. Jacob and other experts say the fixes are inexpensive and can even make money: companies could sell that methane instead of flaring it or allowing it to leak. And the benefits of cutting the pollution are huge and rapid. “If we reduce methane emissions now, we slow the rate of global warming almost immediately,” Howarth says. A United Nations report released in May of this year concluded that a 45 percent reduction in human-caused methane emissions by 2030 would help keep warming to 1.5 degrees Celsius this century, in accordance with the goals of the Paris climate agreement. Such a reduction could limit the impact of deadly heat waves, droughts, flooding and mosquito-borne diseases, potentially saving thousands of lives.

If methane emissions from oil fields are low-hanging fruit, the Permian is a fertile orchard. An April 2020 study led by researchers at Harvard found that the basin emits enough methane to power seven million homes. The work concluded that the rate of methane leakage from the Permian is about 60 percent higher than the national average for oil and gas production sites. As many as one in 10 flares in the Permian malfunction, according to various estimates. And a recent EDF study found that Permian flares operate at only about 93 percent efficiency on average. Even that seemingly small shortfall has a large impact on the climate, EDF scientist David Lyon says.

Permian releases are also much larger, on average, than those in other basins, according to a June 2021 study in Environmental Science & Technology Letters. The basin “is qualitatively different from the other major methane-emitting regions we’ve surveyed around the U.S.,” says Riley Duren, a co-author of the study and a research scientist at the University of Arizona and NASA’s Jet Propulsion Laboratory. Growth rate is a factor; at the height of production in 2019, companies were drilling 600 new wells per month. “There are many more pressure points along that supply chain,” Duren says.

Nearly every component in that supply chain can leak methane. After a well is drilled and fracked, the liquids and gases that come up go through a separator that divides oil, gas and water. Oil goes to tanks, where it waits for trucks, or to a pipeline. Water flows to other tanks or pipelines for disposal. The gas is either flared at the well pad or piped to a network of gathering stations, compressors and processing plants that refine it into the natural gas that heats homes, as well as butane, ethane and propane.

Small flares can be found beside tanks and wells; large ones are found at processing plants, says chemical engineer David T. Allen, director of the University of Texas at Austin’s Center for Energy and Environmental Resources. Gas-powered controllers and valves are found on nearly every piece of equipment across the byzantine infrastructure. “Each controller emits a relatively small amount of methane,” Allen says. “But there are hundreds of thousands of them.”

Credit: Pitch Interactive

Accurate Detection

This unfathomably large set of potential methane leaks is why scientists, environmental groups and some large fossil-fuel companies are pushing for ever sharper surveillance of the Permian. So far aerial surveyors such as Scientific Aviation can trace emissions only to a general area and not to a specific piece of equipment, unless it is an obvious and isolated flare pipe like the one I saw. “We can circle a one-kilometer radius of land and tell you something is definitely happening there,” says Mackenzie Smith, a senior scientist at Scientific Aviation, “but everything in the Permian is so dense that there might be 20 sites in that circle.”

The ubiquity of compact devices makes it that much more important to have high-resolution monitors. In a recent demonstration on a Zoom call, Duren showed me a video of the Permian shot from about 5,200 meters up by planes equipped with NASA-built imaging spectrometers, which detect methane and other gases based on the way they interact with light. The familiar circuit-board-like landscape appeared, but it was overlaid with bright red plumes where methane was leaking. “It looks like there are wildfires everywhere,” he said.

The resolution is about three to eight meters, far sharper than most current satellites and low-flying aircraft. But even that precision is not quite enough to isolate point sources. “It can be difficult to determine the root cause without additional, higher-resolution data,” Duren says. Also, infrastructure is constantly being added, which can make images even a few months old obsolete. Some of the planes now carry high-resolution cameras that map equipment when the spectrometers detect gas.

Another challenge is that many sources are intermittent and unpredictable. Half of the emitters are active only one quarter of the time, Duren says. EDF, which has sponsored research by Jacob, Allen, and others, has also found a concerning number of superemitters that vent significant amounts of gas. To be effective, methane monitoring really needs to operate continuously, at least on a daily basis, over large areas.

That is where satellites come in. Today’s satellites can capture emissions only across broad regions. In 2018 and 2019, for example, Jacob used the European Space Agency’s TROPOMI satellite to make some of the best large-scale measurements of leaks from the Permian. But TROPOMI’s resolution is only about 5.5 by seven kilometers, an area that could hold dozens of oil and gas sites.

Scientists will soon launch a new generation of sensors that can pinpoint individual facilities. Carbon Mapper, a collaboration by NASA, satellite company Planet, the University of Arizona, Arizona State University, the state of California, and others, will launch two satellites in 2023. Several more will follow in 2025 and beyond until Carbon Mapper has at least 18 craft flying through space. Eventually the constellation will provide daily sampling of 80 percent of the largest-known methane and carbon dioxide emissions areas around the globe, which occupy 7 to 10 percent of Earth’s populated land area.

Each image pixel will cover a square 30 meters on a side. The consortium will make data open so regulators, companies, environmental groups and the general public can search a Web site and track emitters. NASA and Planet are procuring components, and assembly and testing will begin next year. Meanwhile the consortium continues to conduct aerial surveys.

Oil pumpjacks, powered by an electric motor or combustion engine, typically nod up and down roughly 20 times a minute, drawing one to 10 gallons of fluid with each stroke. Credit: Nick Simonite

EDF also plans to launch its own satellite, MethaneSAT, in 2023, supported in part by $100 million from Amazon founder Jeff Bezos’s Earth Fund. The hardware, now in production, will precisely quantify the volume of emissions over regions worldwide. EDF will make the data publicly available online.

Once both groups of satellites are operating, they will complement each other. “Imagine you’re looking down from space and taking pictures of the Permian with two cameras: a camera with a medium- to wide-angle lens and a camera with a telephoto lens,” Duren says.

Some oil and gas companies are testing new technologies on their own. Houston-based TRP Energy is experimenting with aircraft, drones and ground-based sensors to monitor its emissions. Co-founder Randy Dolan says preventing and repairing leaks is a priority because “by reducing methane intensity, natural gas will remain the most attractive bridge fuel as we go through this global energy transition.”

In recent years environmental advocates have questioned the idea that natural gas has only a modest climate impact. Cleaning up operations might also be a response to investors who are demanding that companies focus on green energy; in May 2021 ExxonMobil shareholders elected three board members who pledged to steer the company away from oil and gas.

Dolan predicts that companies will end up using their own combinations of technologies to stay on top of leaks. Dallas-based Pioneer Natural Resources conducts annual flyovers of its largest Permian facilities, and if spectrometers show high readings, the company sends in a ground crew with special cameras to pinpoint trouble spots.

ExxonMobil, Pioneer, Chevron and others are working with Allen to test a ground-based, continuous-monitoring system called Project Astra. The goal “is to find superemitters—find them fast, and then you can get them fixed fast,” Allen says. This fall the group will deploy about 50 to 100 ground-based sensors across up to 50 square kilometers of the Permian that contain roughly 100 oil and gas sites. The focus is unmanned installations such as well pads that have unintended emissions. Processing plants have employees who can catch such malfunctions, Allen explains, but “a well site may see a person only infrequently.”

A typical sensor will be small, solar-powered and attached to a pole, sending real-time measurements via cellular networks. Every day operators will see whether a site is operating properly, possibly malfunctioning or abnormally emitting methane. Researchers will test several types of sensors, including an inexpensive metal-oxide sensor developed by Scientific Aviation, which is also testing its own continuous-monitoring system called Project Falcon. “We’re really excited to see if the technology gets off the ground,” says Mark S. Berg, executive vice president of corporate operations at Pioneer. “It’ll be a lot more effective and a lot more cost-effective” than aerial surveys and private satellite data that some companies are now using, he says.

Keeping Emitters Honest

Whether companies follow through remains to be seen. And not all fossil-fuel companies are motivated to reduce emissions. Small firms that operate only a few wells might not have the resources. Sharon Wilson, a senior organizer for environmental group Earthworks, knows the vagaries firsthand. Every few months she loads her rented SUV with camera equipment and drives six hours from her home in Dallas to the Permian. She has worked for years to show that emissions are higher than official government measurements indicate.

Last March, I joined Wilson and two of her colleagues for several days of fieldwork near Pecos, Tex., a city roughly 120 kilometers southwest of Odessa that claims to be the site of the world’s first rodeo. “Do you smell that?” Wilson asked on our first evening as she pulled her white vehicle off a dusty dirt road. We were slowly cruising in twilight along oil and gas pads not far from our hotel. The wind brought in a strong sulfurous odor that quickly made our eyes water. Methane is odorless, but it is often accompanied by foul compounds such as hydrogen sulfide.

Wilson, in her 60s, with flowing gray hair, grabbed her gas-imaging video camera, which looks like a camcorder. She got out of the car and aimed it at a flare about 200 meters away. At that distance the pipe resembled an oversized match standing on end, with orange flames streaming from the top. It roared and whistled as loudly as a low-flying 747. Peering through her camera, which records infrared wavelengths humans cannot see, Wilson assessed that the flare was burning cleanly and that nearby tanks were not leaking. We got back into the SUV and inched down the empty road while she kept her camera on, searching for the smelly culprit. Soon she spotted a pipe that to us looked unlit, but the camera revealed a ghostlike cloud rippling into the air from the top: emissions that should not have been there.

Credit: Pitch Interactive; Sources: “Idle and Orphan Oil and Gas Wells: State and Provincial Regulatory Strategies.” Interstate Oil and Gas Compact Commission, 2019 (2018 data) and 2020 (2019 data); “Areas of Historical Oil and Gas Exploration and Production in the United States,” by Laura R. H. Biewick, U.S. Geological Survey (primary historical reference)

We returned the next day. Again, the pipe appeared inactive, but the camera captured clouds of billowing gas. Wilson marked it on a digital map.

Wilson hunts for and tracks sites that regularly emit large amounts of methane. She reports them to companies, often including video as documentation. She also sends her findings to the Texas Commission on Environmental Quality, which regulates the air Texans breathe, and the Railroad Commission of Texas, formed in 1891 to regulate railroads but which today oversees oil, gas and mining industries. Well pads, she says, multiply so quickly that regulators cannot keep up. Sometimes when she calls, “they can’t find the site in their records,” she says. “That’s a problem. They don’t know what’s going on. They can’t even begin to regulate this mess out here.” She often has to make multiple complaints and notify local news outlets before companies take action.

Operators are always unhappy to see her. One afternoon I was driving, and we pulled off the road so Wilson could film some tanks. A man in a crimson pickup truck pulled up behind us, jumped out of his cab and began waving his arms wildly, motioning for us to leave. “Get out of here, Earthworks,” he said, walking up to Wilson’s window and blocking her camera lens with his hand.

“That’s very mature,” Wilson told him. She reached for her iPhone and began to record him. “What are you trying to hide?” she asked.

The man, in his 20s, bearded and with pale blue eyes, backed off but warned her that she was on private property. Wilson reminded him that we were parked on a public Texas road and that she was a Texan. “Texans believe in oil and gas,” the man scolded as he climbed back into his truck and drove off.

Despite her work, Wilson has given up hope that the industry will operate cleanly. To her, the upcoming monitoring technologies are a waste of resources that will only delay the world’s transition to renewable energy. By the time the new satellites go up, she says, methane emissions will be even greater. Wilson thinks fracking, new drilling permits and other fossil-fuel development should stop altogether. She says President Joe Biden should declare that climate change is a national emergency so he can use expanded powers to reinstate a ban on crude oil exports, imposed in 1975 after the first U.S. oil crisis. “When that ban was overturned in 2015, it charged the Permian Basin fracking boom,” she says.

Tougher Controls

New monitoring methods and the data they can generate may be pushing companies and regulators to act. For example, ExxonMobil and Chevron have promised to cut emissions in half by 2025 and 2028, respectively, and to end routine flaring by 2030. But a recent analysis by two nonprofit sustainable energy organizations, Ceres and the Clean Air Task Force, revealed a surprising pattern: some major oil and gas companies are selling their most highly polluting assets to smaller, lesser-known firms that continue operations. Ceres and the task force found that 195 of the smallest producers account for 22 percent of U.S. emissions but only 9 percent of production.

Last November the Railroad Commission began requiring operators to submit more specific information to justify flaring or venting. It also launched its own drone program during the pandemic to track emissions from well blowouts and from other emergencies.

New Mexico, home to a large chunk of the Permian, issued new rules in May 2021 that require oil and gas companies to capture 98 percent of natural gas emissions and bar the firms from venting or flaring except during emergencies. It is unclear whether the state has enough inspectors to keep tabs on bad actors, however.

Federal rules are in flux. Under President Barack Obama, the EPA passed a regulation requiring oil and gas operators to perform leak detection and repair twice a year for equipment installed after 2015. President Donald Trump rescinded those rules at the end of his term, but in late June, Biden signed a bill from Congress that reinstated them. Policy watchers think the Biden administration may extend the rules to older equipment, too.

Scientists hope that the satellites and open data will not only clean up the Permian but also show the rest of the world how to better maintain its fossil-fuel infrastructure. Methane emissions are a global problem that needs a global solution. In 2020, for example, European Space Agency satellites found large plumes of methane coming from Russia’s Yamal pipeline that supplies Europe with gas from Siberia. The Carbon Mapper and MethaneSAT technology will eventually provide regular measurements of greenhouse gas emissions in major fields worldwide.

Howarth says a big problem with the Obama-era regulations was that there was no built-in verification mechanism. The government left it up to companies to report how much flaring and venting they were doing. Soon “anyone who has that [satellite] information can go and determine whether or not the industry self-reporting is accurate. I think that’s a huge game changer,” he declares. “When company X says it never vents, you can say, ‘Well, that’s not true. Here are the satellite data.’ And that, presumably, would lead to action.”

Anna Kuchment is a contributing editor at 鶹ýAV and a staff science reporter at the Dallas Morning News. She is also co-author of a forthcoming book about earthquakes triggered by energy production.
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鶹ýAV Magazine Vol 325 Issue 3This article was originally published with the title “Methane Hunters” in 鶹ýAV Magazine Vol. 325 No. 3 (), p. 62
doi:10.1038/scientificamerican0921-62