Tag Archives: leak

Inactive oil wells are a big source of methane emissions

Even when you’re done with an oil well, you’re not really done with it. Idle wells could still be leaking methane, a potent greenhouse gas, into the atmosphere, according to a new study carried out on oil wells in Texas.

Image credits: The Great 8 / Flickr

Amy Townsend-Small, an associate professor of geology and geography in UC’s College of Arts and Sciences, has been studying leaky oil wells for a few years, finding that some of them are still leaking methane years after the activity has been shut down. But this is the first time she was granted access to study wells on private land.

“Nobody has ever gotten access to these wells in Texas,” Townsend-Small said. “In my previous studies, the wells were all on public land,” Townsend-Small says.

There were reasons to suspect that things were not alright in Texas. A 2016 study by Townsend-Small found a similar issue in inactive wells she tested in Colorado, Wyoming, Ohio and, Utah, which leak methane equivalent to burning more than 16 million barrels of oil — and that’s according to conservative government estimates.

In Texas, things were just as bad, if not worse.

“Some of them were leaking a lot. Most of them were leaking a little or not at all, which is a pattern that we have seen across the oil and gas supply chain,” Townsend-Small said. “A few sources are responsible for most of the leaks.”

The average leaking rate was 6.2 grams per hour, although seven had methane emissions of as much as 132 grams per hour. If the same rate were to be consistent across all wells in Texas, it would be the equivalent of releasing 5.5 million kilograms of methane per year, the equivalent of burning 150 million pounds of coal.

In addition to the methane, Townsend-Small discovered another problem: five wells were leaking a brine solution onto the ground, in some cases creating large ponds, wreaking havoc on the nearby environment.

“I was horrified by that. I’ve never seen anything like that here in Ohio,” Townsend-Small said. “One was gushing out so much water that people who lived there called it a lake, but it’s toxic. It has dead trees all around it and smells like hydrogen sulfide.”

This isn’t the first time the problem was highlighted by researchers. Time and time again, studies have revealed that oil wells are leaking methane, and authorities are underestimating the problem. Across the US and Canada alone, there are millions of inactive oil wells, hundreds of thousands of which are undocumented. Many of these are improperly sealed and are continuously leaking methane into the atmosphere.

According to conservative estimates, these uncapped wells are responsible for 4% of the US total methane emissions, but the situation could be much worse, and those responsible for the wells are reluctant to offer external access to monitor the leaks. Even this study, wouldn’t have been possible without media organizations that wanted to explore the environmental impact of oil wells and arranged with property owners to allow Townsend-Small to carry out measurements. But there’s also some good news hidden in this study. The good news is that since a few of these wells are responsible for a majority of emissions, they could be prioritized and capped.

President Joe Biden’s stimulus plan includes $16 billion for capping abandoned oil and gas wells and mitigating abandoned mines. Inactive oil wells produce less methane than active ones, but it’s one way to reduce greenhouse gas emissions. With studies like this one, the more problematic ones could be prioritized. In addition, infrared camera inspections could help identify leaks and monitor wells.

The study was published in the journal Environmental Research Letters.

Small air leak identified aboard the International Space Station — astronauts are not in danger

NASA reports that crewmen aboard the International Space Station were woken up on Monday by ground crew — to fix an air leak.

The International Space Station. Image via Pixabay.

The leak has been under investigation for several weeks now, the agency notes, but the rate of air loss seemed to increase on Monday, causing ground control to intervene. Despite this, the leak is in no way an immediate danger to the lives of the crew and has since been tracked to the Zvezda (“Star”), a module on the Russian side of the ISS that houses life support equipment and quarters for two crewmembers.

Airloss

“Late Monday night, the Expedition 63 crew was awakened by flight controllers to continue troubleshooting a small leak on the International Space Station that appeared to grow in size,” NASA explained in a statement on Tuesday.

“Ground analysis of the modules tested overnight have isolated the leak location to the main work area of the Zvezda Service Module.”

The crew collected readings from various locations inside the station using an ultrasonic leak detector, closing hatches between modules one by one as they went. In the end, they managed to narrow the search down to the Zvezda module.

Throughout the night on Monday, the module was kept isolated and pressure measurements were performed remotely to identify the leak’s location. By morning, the checks were complete, and the crew re-opened the hatches between the US and Russian segments of the ISS and went back to their regular, space-faring lives.

This isn’t the first time astronauts aboard the ISS needed to contend with a leak. Back in 2018, a 2mm drill hole was discovered in the Russian Soyuz craft while it was docked to the station. This hole was patched with epoxy resin and tape. The cause, and whether this hole was caused by accident or with intent, has yet to be determined.

The current leak was likely caused by a mechanical or manufacturing defect.

“The size of the leak identified overnight has since been attributed to a temporary temperature change aboard the station with the overall rate of leak remaining unchanged,” NASA explains.

Caught red-handed: emissions from ammonia fertilizer plants were 100 times higher than the industry’s self-reported estimate

Methane emissions are massively underreported by the industry, a new study using Google Street View cars found. Even the EPA estimate, which is much more realistic, is still three times lower than what researchers found.

“We took one small industry that most people have never heard of and found that its methane emissions were three times higher than the EPA assumed was emitted by all industrial production in the United States,” said John Albertson, co-author and professor of civil and environmental engineering. “It shows us that there’s a huge gap between a priori estimates and real-world measurements.”

The methane hotspots of continental USA. Image credits: NASA/JPL.

Although the world has made some progress in reducing our consumption of coal, the use of natural gas has grown in recent years, particularly due to increased shale gas extraction and a general perception that gas isn’t as dirty as coal.

There is some truth to that idea. In a new, efficient power plant, natural gas emits 50 to 60 percent less carbon dioxide (CO2) when compared with emissions from a typical new coal plant. It’s still bad, just not as bad as coal. But if emissions are overlooked at any point in the extraction, processing, and distribution process, it could drastically change the math. A new study seems to indicate that just that — except it’s not about CO2, but methane.

While CO2 can affect the atmosphere for centuries or even millennia, methane only persists for about 12 years. However, it’s still an important consideration when it comes to climate change, particularly in the more immediate future. CO2 is usually painted as the bad boy when it comes to global warming, but as a greenhouse gas, methane is 30 times more powerful than CO2.

The globally averaged concentration of methane in Earth’s atmosphere has increased by about 150 percent since the start of the Industrial Revolution, and while most of the attention is aimed at carbon dioxide, methane is also closely monitored. Though, it might not be monitored closely enough.

For this study, a Google Street View vehicle equipped with a high-precision methane sensor traveled public roads near six representative fertilizer plants in the US to quantify “fugitive methane emissions” — inadvertent losses of gas to the atmosphere. These fugitive emissions can happen due to leaks and incomplete chemical reactions during the fertilizer production process. As soon as researchers found a plume of high values, they would drive dozens of laps around it with the car, to take detailed measurements.

The team found that, on average, 0.34% of the gas used in the plants is emitted to the atmosphere. If the figure is a representative average, then the entire industry would have total annual methane emissions of 28 tons — 100 times higher than the industry’s self-reported estimate. Even the EPA’s estimate (8 tons) is much too conservative.

The fact that methane emissions are so heavily underestimated is concerning and calls for further investigation, the researchers conclude.

How to stop the annoying sound of a dripping tap with science

A leaky faucet is a form of Chinese water torture. *Plink *plink. Doesn’t it sound like popping brain cells? Suffice to say that many a man has been kept awake by this nuisance — but it’s only recently that some brave scientists have finally understood how to stop it. Contrary to previous research, a University of Cambridge scientist learned that the annoying sound is caused by trapped air bubbles beneath the water. Just adding a hint of dishwashing soap to the to the container catching the drips will stop the sound, according to the scientist.

Dr. Anurag Agarwal, a researcher at Cambridge’s Department of Engineering, was once sleeping overnight at a friend who had a leaky roof. Agarwal, who is an expert in the aerodynamics of aerospace, domestic appliances, and biomedical applications, was kept awake by the dripping water. Being an engineer, however, he sought to find a solution.

“While I was being kept awake by the sound of water falling into a bucket placed underneath the leak, I started thinking about this problem,” said Agarwal in a statement.

Instead of plugging the roof, Agarwal went deep at the molecular level. He spoke to a colleague about the physics involved and they both decided to set up an experiment.

Previous studies have proposed that the “plink” sound is caused by the impact of the droplets onto a surface, such as a sink, similarly to how slamming an object against the wall makes a “bang.” Other explanations propose that the plinking sound is generated by an underwater sound field propagating through the water surface, or the resonance of the cavity formed by water hitting a surface.

Agarwal and colleagues set up an experiment using high-speed cameras and high-end audio-capture equipment. Recordings of the dripping water showed that the dripping sound mechanism is actually very different from what was proposed earlier.

“A lot of work has been done on the physical mechanics of a dripping tap, but not very much has been done on the sound,” Agarwal said. “But thanks to modern video and audio technology, we can finally find out exactly where the sound is coming from, which may help us to stop it.”

Remarkably, the observations suggest that the initial splash, the formation of the cavity, and the jet of liquid are all effectively silent. The annoying plinky sound is actually the result of the oscillation, or back-and-forth movement, of as little as one tiny bubble of air trapped beneath the water’s surface. The bubble causes the water’s surface to vibrate in tune with it, which sends acoustic waves to our ears similarly to how a piston triggers an airborne sound. The trapped air bubble needs to be close to the bottom of the cavity caused by the drop impact in order for the “plink” sound to be audible.

The researchers validated their model by halting the sound, they wrote in the journal Scientific Reports. They simply added a small amount of dish-washing soap to the container catching the dripping water.