The oil industry’s practice of burning unwanted methane is less effective than previously assumed, resulting in about five times more greenhouse gas emissions in the United States than previously, according to a new estimate. , the scientist said Thursday.
In a study of the three largest oil and gas basins in the United States, researchers found that methane, a powerful heat-trapping gas that is often a by-product of oil production, was completely removed in a process known as flaring. I found that it doesn’t burn. And they found that, in many cases, flares are extinguished and not reignited, thus releasing all the methane into the atmosphere.
Scientists say that improving efficiency and keeping all flares lit could reduce emissions equivalent to pushing nearly 3 million cars off the road in the United States each year.
“The flare was kind of ‘invisible, out of mind,'” said one of the researchers, Eric A. Court. University of Michigan“But it’s actually more important to the climate than we thought.”
“So if we wipe out our actions with these flares, we can actually have a much better climate impact than we first realized,” said Dr Cort.
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Although more powerful than carbon dioxide, methane is a short-lived greenhouse gas, so efforts to identify and reduce methane emissions have intensified in recent years.
Methane, also known as fossil gas, is a major component of natural gas and can leak into the atmosphere from wells, pipelines and other infrastructure, and can also be intentionally released for maintenance and other reasons. .
But a huge amount is burning.
Flared gas is often produced with oil in oil wells and other industrial installations around the world. There may not be a pipeline or other means to sell it economically, and it is flammable, which creates a safety issue. In that case, the gas is sent through a vertical pipe with an igniter on top and burned.
The International Energy Agency estimated that more than 140 million cubic meters of methane were burned in this way worldwide in 2021. This corresponds to the amount imported by Germany, France and the Netherlands in that year.
If combustion were efficient, almost all methane would be destroyed and converted to carbon dioxide, with less direct climate impact. The Environmental Protection Agency calculated that 98% of the methane released by the flare was destroyed in a study conducted in the 1980s.
But a new study finds that flares are actually much less effective, especially when considering unlit flares. It accounts for 10% of all methane emissions in industry. The findings were published in the journal Science.
The researchers examined operations in the Permian and Eagle Ford basins of Texas and the Bakken Basin of North Dakota. Together, they account for approximately 80% of US flaring. “The idea was that if we could get a good representative sample in these domains, we would have a better idea of what it looked like across the United States,” said Dr. Kort. They flew through the flare in a small plane and sampled the gas plume from the flare.
They found that the burning flare destroyed only about 95% of the methane instead of about 98%. And it turns out that in some basins, his 5% of flares are not lit. This reduced the overall efficiency to about 91%.
Flares can be affected by wind, which can release unburned methane or the presence of other gases. Wind, gas pressure changes, or igniter problems can extinguish the flame, and without regular monitoring, the flare can remain unlit for long periods of time.
Riley Durren Chief Executive Officer carbon mapper, Next year, a nonprofit that will launch satellites to detect and monitor sources of greenhouse gas emissions will study emissions from these oil and gas basins, and for those who know the amount of flaring that has taken place, He said the finding was not surprising.
But the researchers’ comprehensive survey shows that inefficient flaring is “a more systemic problem,” said Dr. Durren, who was not involved in the study.
Elsewhere in the world, there is little direct observational evidence of flare efficiency, Dr. Duren said. But globally, “combustion and flaring are likely to be less efficient than assumed,” he said.