The Gulf of Mexico is littered with tens of thousands of abandoned oil and gas wells, and toothless regulation leaves climate warming gas emissions unchecked.
Out on the deck of a research boat, Tara Yacovitch looked out to the water. In the middle of the Gulf of Mexico, the seascape is peppered with lights. And every light is part of an offshore oil or gas platform.
Locations of existing oil and gas infrastructure in U.S. Gulf of Mexico territory, 2017. (Credit: Deepwater Oil and Gas Production in the Gulf of Mexico and Related Global Trends)<p>Research in other offshore environments from the North Sea in Europe to the Bohai Sea in China indicate a global trend, but EHN focused on the Gulf of Mexico, since that is where the majority of oil and gas drilling occurs in the U.S., and subsequently where the majority of data and research has been collected.</p><p>While active oil and gas wells can also be prone to leakage, leaks from decommissioned and abandoned wells are more pernicious. Though all wells are supposed to be plugged before they are abandoned and decommissioned, the state of those plugs post-abandonment is not monitored. Abandoned wells number in the tens of thousands, with abandonment rates increasing yearly. </p><p>A well could be active for years, even decades, but an abandoned well that has not been properly plugged could leak methane and other harmful gases in perpetuity. Beyond methane, <a href="https://www3.epa.gov/ttn/chief/le/benzene_pt2.pdf" target="_blank">benzene</a>, <a href="https://doi-org.proxy.library.nyu.edu/10.1029/2019GL085866" rel="noopener noreferrer" target="_blank">nitrogen oxides</a>, <a href="https://www.sciencedirect.com/science/article/pii/S1750583618304857?via%3Dihub" rel="noopener noreferrer" target="_blank">carbon dioxide</a> and more all have all been detected in oil and gas well emissions.</p><p>Experts say federal oversight and regulation remain inadequate, allowing industry to continually add to the well count without properly documenting crucial site details. Records on the locations, longevity, and emission volumes for wells are incomplete, but emissions from these sites undoubtedly impact ocean ecology—and some of this methane inevitably gets released into the atmosphere.</p>
Regulatory holes<p> Offshore oil and gas production in the U.S. <a href="https://link.springer.com/chapter/10.1007/978-3-030-12963-7%1F_2" target="_blank">began in the early 20th century</a>, with production in the Gulf of Mexico beginning in the late 1930s. It was not until 1982, however, that the government created the Minerals Management Service (MMS) and passed the <a href="https://www.boem.gov/sites/default/files/uploadedFiles/BOEM/Oil_and_Gas_Energy_Program/Leasing/Outer_Continental_Shelf/Lands_Act_History/federal%20og%20royalty%20mgmt.pdf" target="_blank">Federal Oil & Gas Royalty Management Act</a>, requiring recordkeeping for where and when wells were drilled, and to whom they were sold. </p><p> In 2010, MMS split into what would become BOEM, BSEE, and the Office of Natural Resources Revenue. All U.S. federal waters are now leased out by BOEM, and all wells and platforms are monitored and regulated by BSEE. </p><p> Once leases are finalized, companies can drill exploration wells—the initial boreholes used to determine whether an area will be profitable. </p><p> And what that exploratory well looks like depends on the geology of where you're drilling. "In offshore environments it can be thousands, maybe even 20,000 or 30,000 feet underwater. And how far into the ocean floor you drill will again just depend on that geology," <a href="https://www.lsu.edu/eng/pete/people/faculty/williams.php" target="_blank" rel="noopener noreferrer">Wesley Williams</a>, an engineer at Louisiana State University, told EHN </p><p> In the early days, companies drilled exploration wells with little to no concern, Williams said—"there's some areas where we joke that it's like Swiss cheese." But now, regulators are more scrupulous. </p><p> As they drill, whether exploratory or not, companies consistently check for economic viability, Williams said. When that economic viability tips over to red, the owners either sell or decommission. </p><p> But what is considered "economically viable" differs from company to company. Leases and rights to drill at one site may pass through multiple companies over the years. Once a well stops generating interest or profit potential, it is decommissioned. </p><h3><em>Related:</em> <a href="https://www.ehn.org/fracking-methane-leaks-2645817287.html" target="_blank"><em>Oil and gas methane emissions in US are at least 15% higher than we thought</em></a></h3><p> Every well is supposed to be decommissioned when no longer active in concordance with federal law. Platforms at the surface are supposed to be removed, and boreholes in the ocean floor need to be plugged with cement or a similar material. But not every well is decommissioned properly. Sometimes, especially if the parent company goes out of business, they are simply orphaned, left to idle and leak until the government handles plugging. </p><p> Erik Milito, president of National Ocean Industries Association wrote EHN in an email: "Between Federal plugging and abandonment regulations, which require the installation and testing of barriers, and the natural tendencies of methane, the likelihood of methane emissions escaping from oil and gas activities on the sea floor is extremely low." </p><p> Sandy Day, BSEE's press secretary wrote EHN in an email that "BSEE inspects all offshore facilities at least once per year; and inspects drilling rigs at least once per month. BSEE conducts pollution surveillance and offshore site-specific inspections using helicopters flying from district office locations around the Outer Continental Shelf." Day did not address how they monitor abandoned or orphaned wells, specifically. </p><iframe src="https://ourworldindata.org/grapher/ch4-concentration" loading="lazy" style="width: 100%; height: 600px; border: 0px none;"> </iframe><p> But federal policies for these wells are "difficult to administer and it's easy to evade," <a href="https://meganmilliken.wixsite.com/mysite" target="_blank" rel="noopener noreferrer">Megan Milliken Biven</a>, an energy policy researcher and former BOEM employee, told EHN. And these agencies' policies are basically all "beyond the scope and capability of the resources the agency has." </p><p> She added that most of these agencies' "due diligence" safety evaluations are more about giving themselves a pass than actually discerning risk. BOEM has a guidebook to evaluate the environmental impact of any drilling operation, "and I would say that that document doesn't exist to actually remove or mitigate any kind of risk. It's only to state the risk so that when someone tries to sue the agency, they can say, 'look, we looked at the risk.'" </p><p> Milliken Biven also said that it's hard to define what holes there are in the system, because "that assumes that there is a standard for plugging and abandonment, that assumes that there is a standard for checking for leaks, that assumes that there is a standard for site clearance and restoration...but there is none." </p>
“Super-emitters” and the undocumented<p>The <a href="https://www.globalmethane.org/documents/analysis_fs_en.pdf" target="_blank">Global Methane Initiative</a>, an international effort to reduce methane emissions, estimates about 20 percent of human-caused methane emissions come from the oil and gas sector. That's likely an underestimated figure, Yacovitch told EHN, "because there's really not that much data on offshore assets—the field of measuring emissions, particularly in the Gulf of Mexico, is fairly new."</p><p>Yacovitch and her team randomly selected and studied 103 sites, looking at air quality from the platforms as seepage on the ocean floor is hard to measure. The team looked at a mix of both active and decommissioned, shallow and deep, and found <a href="https://pubs.acs.org/doi/abs/10.1021/acs.est.9b07148" target="_blank" rel="noopener noreferrer">platforms emitted methane at widely ranging rates</a>: from zero to 190 kilograms per hour. And the top 2 percent of emitters accounted for 20 percent of the total methane emissions. </p><p>The data show that not every well, orphaned or not, is guaranteed to leak. But when a well does leak, there is huge variability in emissions.</p>
Drilling rig in the Gulf of Mexico. (Credit: Tara Yacovitch/Scott Herndon)<p>They only surveyed 103 areas—so there is a chance that, though they randomly selected their surveyed regions, their data may not be an accurate representation.</p><p>Nonetheless, the study points to an incredible problem. The top 2 percent of emitters, so-called super-emitters, leak very high levels of methane, but are largely unidentified in a literal sea of sites. While 2 percent may sound small, when the total is 55,292 wells in federal waters, that amounts to 1,104 super-emitters in national waters.</p><p>What's more, "a lot of wells are undocumented," <a href="https://www.mcgill.ca/civil/mary-kang" target="_blank">Mary Kang</a>, an environmental engineer at McGill University, told EHN. Kang has years of research experience looking at leaky, abandoned oil and gas wells. "You go out and you don't find them. And then you go somewhere else looking for one, but you find 10 others."</p><p>An <a href="https://pubs.acs.org/doi/abs/10.1021/acs.est.0c00179" target="_blank" rel="noopener noreferrer"><em>Environmental Science & Technology</em> paper</a> from earlier this year states that "current U.S. government inventories overestimate the number of oil and gas platforms in federal waters while missing platforms located in state waters." Scientists found that more than 1,300 offshore facilities were missing from government documentation. </p><p>These facilities are likely older and therefore larger, with disproportionately high spikes of methane emissions, from early industry years when tracking measures were even less stringent. </p><p>The authors suggest that U.S. methane emissions for the country's whole natural gas supply chain are as much as 60 percent greater than the U.S. Environmental Protection Agency Greenhouse Gas Inventory.</p>
Energy companies working in the Gulf of Mexico produce about 1.7 million barrels of crude oil per day. (Credit: Bureau of Safety and Environmental Enforcement)<p>Individual states are responsible for sites in their own waters, but as far as monitoring and tracking their wells, "different states definitely do it differently, and some do it almost not at all," <a href="https://www.linkedin.com/in/chris-konek-7029851/" target="_blank">Chris Konek</a> told EHN. Konek manages the oil and gas methane science studies at the Climate & Clean Air Coalition (CCAC), which is part of the UN Environment Programme. He said identifying where wells are in the vast ocean is a difficult undertaking.</p><p>Yacovitch and her team experienced that challenge. When trying to navigate to survey sites, the team found discrepancies between where government records said oil and gas platforms were versus where they are. "Sometimes we would say, 'We swear there's a platform out here,' but we'd go and there's nothing there," Yacovitch said.</p><p>A lot of research in this area thus far has focused on measuring how much methane each well is emitting, said Kang, who has spent years researching abandoned oil and gas wells. But, terms like "leakage" are poorly defined.</p><p>"If you see no methane emissions on the ocean floor, or at the water's surface, does that mean there was no leakage? No, it doesn't," Kang said. An absence of gas bubbles coming up to the ocean's surface and low methane measurements in the air do not guarantee there is zero gas escaping.</p><p>Kang also said there is no standard definition for what flow rate constitutes leakage across the industry. If you look at just high emitters, depending on how you define "high," then leaky wells are just 10 to 20 percent. But depending on how you define that threshold for leakage, the proportion of leaky wells could go up to 50, maybe 80 percent. "The bigger questions are, how many wells are out there, and how long are they emitting for?" Kang added.</p><p>There are many wells that are active for just a few years, if at all, but once a well is abandoned, "they're going to be abandoned for decades and centuries," Kang said.</p><p>Industry reports show pretty consistent numbers of newly drilled or active wells in a given area of oil and gas production over time. But if you read between the lines, that means that the numbers of abandoned and decommissioned wells are always growing.</p>
“A multi-billion dollar issue”<p>There is an upcoming wave of wells that will be plugged and abandoned in the coming years—a surge that science and industry have long seen coming. According to a June article in <a href="https://www.worldoil.com/news/2020/6/5/underperforming-offshore-wells-rack-up-over-100-billion-in-abandonment-liabilities-worldwide" target="_blank">World Oil</a>, "In the U.S. Gulf of Mexico, which generates about 15 percent of the nation's output, explorers are expected to spend about $1 billion a year over the next half decade to decommission hundreds of wells."</p><p>A <a href="https://doi.org/10.1016/j.energy.2018.08.128" target="_blank" rel="noopener noreferrer">2018 paper</a> says that "in recent years, the shallow water region has witnessed record levels of decommissioning activity due to aging fields, sustained low oil and gas prices, and greater regulatory oversight and scrutiny." Moreover, "more than 40 percent of all decommissioning activity to date has occurred over the past decade." </p><p>"From a strategic point of view, now is a very unique opportunity for us to admit there's a problem," said Williams, the LSU engineer. Every well ever drilled will need to be plugged. With a cascade of plugging projects imminent, it is imperative now more than ever to nail down proper methodology.</p><p>One <a href="https://www.sciencedirect.com/science/article/pii/S0920410518309173" target="_blank" rel="noopener noreferrer">2019 paper</a> reviewing plug and abandonment methods found that, despite many layers of cylindrical casings and cement barriers—the industry's most-used technique for plugging, many wells still leak because of chemical stressors and the constant shifting tectonics of the Earth. </p><p>"Just because you plug a well, that doesn't mean it's plugged forever," Williams said. "It's plugged for as long as that piece of material is going to last."</p><p>It's a fallacy to think a company will clean up their mess once they no longer want to produce oil or gas, said Milliken Biven. </p><p>Evidence is mounting that the story for these wells rarely ends cleanly after plugging and abandonment.</p>
Drilling rigs in the Gulf of Mexico. A report from this year found more than 1,300 offshore facilities were missing from government documentation. (Credit: Tara Yacovitch/Scott Herndon)
(Credit: Tara Yacovitch/Scott Herndon)
(Credit: Tara Yacovitch/Scott Herndon)
Tara Yacovitch and her team found the top 2 percent of emitters, so-called super-emitters, leak very high levels of methane, but are largely unidentified in a literal sea of sites, (Credit: Tara Yacovitch/Scott Herndon)
BSEE platform inspection. (Credit: Bureau of Safety and Environmental Enforcement)<p>Wells in state waters may be all the more problematic, since they are usually older and probably did not have to adhere to modern safety and environmental standards.</p><p>"I did an estimate, just a back-of-the-envelope calculation, and I think in Louisiana it's easily a $2-5 billion-worth problem," said Williams. "And that is just Louisiana. Nationwide, it's definitely a multi-billion dollar issue."</p><p>Furthermore, Williams wants oil and gas to take a leaf out of nuclear's book: Nuclear energy producers will often think in terms of life cycle costs, taking a small percentage of energy sales and saving that money for disposing nuclear waste. The fossil fuel industry has no equivalent, he said, so by the time it is time to retire a site, "there has been no money saved by the regulator or by the government or by anybody to help with those costs of plugging and getting the areas cleaned up."</p><p>Konek added that some of the most potentially effective strategies are mostly non-technical, like incentivizing methane storage: "In certain places there's a lack of infrastructure to get gas to market, and so you have companies that are letting that go." Finding more efficient ways to store and use that gas could convince companies to keep better track of the methane gas coming from their wells.</p><p>As it stands, letting methane pool and seep means letting all that methane get to the atmosphere. "Depending on the water depths, we estimated in total, probably about a third of the gases that is emitted at the sea floor will enter the atmosphere," <a href="https://www.geomar.de/mhaeckel" target="_blank">Matthias Haeckel</a>, a marine geochemist and an author of the North Sea hydroacoustic imaging study, told EHN. At shallow water depths, around a hundred feet or less, all that emitted methane will get to the atmosphere in a few months, he added.</p><p>But even if methane doesn't make its way from the sea floor to the atmosphere, the act of drilling results in fractures and pathways for gas to pool and accumulate in ways that it otherwise would not, potentially creating risk of blowout events, <a href="https://www.marinegeophysik.ifg.uni-kiel.de/en/team/christophboettner" target="_blank" rel="noopener noreferrer">Christoph Böttner</a> told EHN. Böttner is a marine geoscientist at the University of Kiel and one of Haeckel's co-authors.</p><p>In their study, Böttner and Haeckel's team used hydroacoustic imaging to look at marine sediments and estimate where pools of methane lie in the ocean floor. Using this technique in tandem with existing regional seismic data, they said, could guide industry away from potentially problematic areas. Layer on satellite imaging and infrared spectroscopy, and you have a much better chance at getting an accurate idea of where gas flow exits.</p><p>Uncontrolled flow of natural gas, including methane is also a leading hazard for oil and gas workers. The <a href="https://www.nytimes.com/2020/04/19/climate/deepwater-horizon-anniversary.html" target="_blank" rel="noopener noreferrer">Deepwater Horizon</a> blowout event is still salient a full decade later. But measures to prevent future blowouts have actually decreased in the last decade. <a href="https://apnews.com/article/8181adee796a45706cb4be265ca1e0d1" target="_blank" rel="noopener noreferrer">According to the AP</a>, "inspections fell from 4,712 in 2013 to 3,717 in 2019," and while in 2016 the government required companies to test their blowout preventers every 14 days, "the Trump Administration allows companies to test every 21 days, saying more frequent testing would risk equipment failure."</p>
BSEE engineers inspecting a platform in Ingleside, Texas in 2015. (Credit: Bureau of Safety and Environmental Enforcement)