The most widely-used technology for detecting methane leaks from oil and gas operations does not work reliably in extremely cold weather—like on Alaska's North Slope, according to recent research and the industry's own reports.
When the weather hits the extreme lows common around Prudhoe Bay, when the winds whip and the sun dips below the horizon for a few months, the infrared technology required to look for methane leaks isn't always able to find them.
"A lot of the equipment just doesn't function well at -40 or -50," said James Plosay, who manages the air permits program for the Alaska Department of Environmental Conservation's Division of Air Quality.
Across the country, recent reports have found that methane leaks from oil and gas infrastructure are under-reported. One recent study by the Environmental Defense Fund (EDF) found that as much as five times more methane could be leaking from sites in Pennsylvania than industry reports to state regulators.
But what's happening on Alaska's North Slope represents a unique problem—one of a litany of challenges facing operators in the punishing conditions there—and raises questions about how accurate estimates of fugitive emissions are in a place where the climate change stakes are among the highest.
Methane is a potent climate forcer. Though it's a short-lived climate pollutant that does not remain in the atmosphere as long as carbon dioxide, methane's impact on climate is much greater than CO2 in the short-term. In the Arctic, where temperatures are rising at least twice as fast as the rest of the world, methane alone has caused a half a degree Celsius of warming.
Since 2008, the oil and gas industry in the United States has been required to use Optical Gas Imaging technology to detect methane leaks. Arvind Ravikumar, a Stanford post-doctoral fellow who studies this technology and its ability to detect leaks, described the tool as essentially a "handycam, but with infrared so the methane becomes visible."
The company that makes the most widely used cameras, FLIR Systems, Inc., said its product works in a variety of climates, including Alaska's North Slope and in Canada, with special handling procedures. It did not address the concerns raised by the recent reports when asked about them.
The problem of these leaks represents a common ground between environmentalists and industry, in that both see it as a problem that should be solved. Methane leaks mean lost profits to the industry. "It's in their best interest to keep leaks down," said Plosay. "But of course, it's a huge industrial process and leaks happen."
2016 Rules Required Leak-Detection Tech
Since its introduction over a decade ago, Optical Gas Imaging technology has been in widespread use. In 2016, when the Obama Administration passed rules to reduce methane emissions, it included a requirement that operators inspect facilities twice a year using instrument-based detection. It called for the use of infrared cameras or other approved methods.
In 2015, as part of the rulemaking process, Laura Perry, the air quality coordinator for ConocoPhillips Alaska, submitted a comment to the EPA in which she explained the problem with the cameras.
"According to FLIR Systems, Inc., the optical gas imaging cameras' operating temperature range is from -4°F to 122°F. This manufacturer does not offer any gas imaging cameras designed to operate in temperatures below -4°F."
On the North Slope in the winter, it is normal for temperatures to be far below -4°F, Perry wrote. She also pointed out that the camera is designed to operate when wind speeds are less than 8 mph, which is gentler than the ordinary winds of an Alaskan winter.
In light of this—and the costs associated with the rule's requirement to shut down facilities to repair leaks, which Perry wrote would have an economic impact on Alaska's economy—Perry asked that the North Slope be exempted from the 2016 methane rules.
Using a FLIR camera, EDF captured California's Aliso Canyon methane leak that started in 2015 and wasn't visible to the naked eye. Credit: Environmental Defense Fund
Though the request wasn't granted in full, the final rule did exempt natural gas processing plants on the North Slope from the rule.
In late February of this year, that exemption was expanded.
Trump's EPA Loosened Inspection Rules
While the Trump administration's attempt to overturn Obama's methane rules is facing legal challenges on several fronts, the EPA issued two narrow amendments to the Fugitive Emissions Requirements of the rules.
One amendment got rid of a requirement that leaks had to be repaired during emergency shutdowns. Instead, they can now be repaired during the next planned shutdown or within two years, whichever is earlier.
And on the North Slope, another amendment gives operators more time to conduct inspections to new or modified wells, so if a well is drilled in winter, instead of having to inspect it within 60 days, operators now have six months.
Infrared footage shot by EDF reveals the giant methane leak from Aliso Canyon. Credit: Environmental Defense Fund
An EPA fact sheet explaining the changes to the rule ascribed this change to reports from industry that methane cannot be detected as well during the winter. A 2017 comment from the American Petroleum Institute had cited Perry's 2015 letter about the inability to detect leaks in extreme cold. (In its comment, API also asked that other locations that experience extreme cold, like North Dakota and Wyoming, be exempted. That request has not been granted.)
"Both amendments are expected to result in cost savings for the oil and gas industry, as well as reductions in climate benefits that would occur from reducing methane emissions," the fact sheet says. On the North Slope, the EPA estimates the change will save the industry approximately $24,000 a year in compliance costs, and that approximately 34 tons of methane per year that would have been captured will be released into the atmosphere as a result.
Where Are the Leak Risks?
In her 2015 letter, ConocoPhillips' Perry wrote that there are certain things that operators do on the North Slope that help make up for the issues around leak detection in winter. For instance, she wrote that processing facilities are fully manned around the clock and are entirely enclosed.
"Because they are all enclosed and manned, liquid and gas leaks cannot be generally tolerated so the facilities (and manifold buildings at the drill sites) contain gas detection equipment that alert operators to leaks so they may be expeditiously repaired," she wrote.
While true, Alaska EPA inspector John Pavitt said there are plenty of other opportunities for gas leak on the North Slope. "If it's a gas well, I can't think of an example where one is enclosed," said Pavitt, who has been doing inspections in Alaska for 25 years. "They're out and exposed to the weather."
In fact, he said, there are ample opportunities for leaks in the equipment as the wells pull up a mixture of oil, gas and water which then has to be separated. "As you think about the infrastructure on the North Slope, a lot of the work being done is to separate those streams and to handle them and do what needs to be done," he said. "There's potential for leaks in any of the equipment handling those streams."
Ravikumar, at Stanford, said that heaters used on the North Slope during the winter are prime candidates for leaks, which are currently going undetected. "They often vent methane when they're operating," he said. "We know there are extra emissions sources because of those conditions."
FLIR Stands By Its Technology
The company behind the cameras stands by their ability to function in cold, windy, dark climates. "FLIR Optical Gas Imagers have been proven as a useful and dependable tool by customers in both the Northern Slope of Alaska and in Canada where the conditions can reach extremely cold temperatures," Craig O'Neil, the business development manager at FLIR, wrote in an email.
It's easiest for infrared cameras to detect a methane leak when there is a difference in temperature between the gas and the air at the surface. The bigger that difference (which is known as Delta T) the better. Having sunlight helps—it can warm the surface air higher than the gas—but a lack of it can be useful too, said O'Neil. "In extremely low temperature environments where there is no sunlight, FLIR's camera can possibly operate better as there is a good Delta T since the background is much lower than the escaping gas temperature which could be considerably hotter."
Neither O'Neil nor other representatives from FLIR responded to questions about the concerns voiced by the industry, the EPA and Ravikumar's studies, besides stating that though the cameras might have a reduced battery life in extreme cold, "the camera would still function."
Similar Problems in Alberta's Tar Sands
It's not just the North Slope that faces challenges detecting methane leaks in the winter. The winter conditions in Alberta, Canada, home to the tar sands and a large natural gas industry, can also hamstring the leak-detecting cameras.
Thomas Fox, a Ph.D. student studying methane detection in natural gas fields in Alberta, said that while the temperature there can dip well below zero, the bigger problem in Alberta is the prairie wind. "I've spoken informally to field workers who say if the wind is above 30 km per hour, you shouldn't even go out," he said.
Canada recently released new methane regulations that aim to cut emissions by 40 to 45 percent by 2025. But Fox worries that without the widespread use of technology that is able to measure leaks year-round, that may be hard to accomplish.
"The government has taken this prescriptive approach and said if we take the cameras and go out three times a year and look for leaks, we're going to assume that will lead to the targets we're looking for," Fox said. "But if you don't take into account that the cameras don't work as well in certain conditions you're maybe not going to achieve the targets that you set out to achieve."
What Happens Now?
In the United States, the amendments to the methane rules are raising suspicion among some environmentalists. "Our concern is: What's the real intention behind the rule change?" said David Lyon, a scientist at the Environmental Defense Fund. "Was it a minor technical tweak to address a legitimate issue? Or was it a tactic to start chipping away at the rule, piece by piece?"
He also questioned the knowledge gap on the North Slope and in other cold climates as methane leaks go undetected in the winter. Without functioning cameras, operators are left with audio and visual inspections as the best tool for detection. "They've shown that audio-visual inspections do not work," he said. "That's not a good alternative to finding the leaks."
EDF has partnered with Ravikumar, the Stanford researcher, to evaluate other forms of detection that could have more success in cold climates.
"We're bringing a lot of new technologies together and testing them on performance," Ravikumar said. One that holds promise is a laser-based technology by California-based Picarro.
"The temperature is not an issue for us," said product manager David Kim-Hak. "We can measure methane emission at very cold or low temperatures." But for now, the costs of Picarro's product has been prohibitively high for industry to use. At this point, it's being used more by researchers.
"Our tech is extremely precise and stable. In that sense it's much better and much more advanced than any sensors that you can buy," said Kim-Hak.
"Because of that the price is much higher," he said. "We are slowly moving into a solution that could be more cost-effective for the user."