There are thousands of abandoned and unclosed oil wells in shallow waters, wetlands and offshore areas along the Gulf of Mexico that pose an environmental risk, according to a new study.
A study published in Nature Energy found that there are 14,000 abandoned oil and gas wells in the waters along the Gulf of Mexico and in Alabama, Louisiana and Texas. After collecting data on more than 80,000 wells drilled in the Gulf from the U.S. Bureau of Safety and Environmental Enforcement, the researchers conducted an analysis of the cost of shutting down these idle wells.
While most of the wells were closed, about 14,000 were left open. Closing the wells will prevent environmental damage, but it could cost up to $30 billion, the researchers say.
Unsealed oil and gas wells can leak methane, a powerful greenhouse gas that builds up in the atmosphere. When methane gas accumulates in a smaller space, it can cause suffocation and is also flammable. Wells being near communities and leaking into homes can pose a significant hazard. About 13,000 of these abandoned and unclosed wells are in US federal or state shallow waters. The authors of the study state that priority should be given to these wells when it comes to closure.
“Methane seeps from shallow water infrastructure are likely to come to the surface,” said study author Greg Upton, an associate professor at the Louisiana State University Center for Energy Research, at a press conference. will provide more environmental benefits than costs.”
What factors does the cost depend on?
Previous research has shown that these wells can be a major source of water pollution and leach other toxins, including arsenic. Closing the wells will involve a process in which workers use cement to fill the reservoir from which the oil and gas comes. A plug is placed in the well, Upton says, and then more cement is poured over it. The cost associated with this process is usually determined by how much cement is used and the tools needed to properly plug the well in different locations.
It is even more difficult to plug deep water wells further offshore in the Gulf. Wells in shallow waters represent 90% of the sites surveyed, and closing them will only need 25% of the estimated $30 billion, the team said. “Diving equipment may not be required to reach wells in a swampy environment, but extremely deep water wells are inaccessible even to divers. It requires expensive technologies such as remotely operated vehicles,” he writes.
Unfortunately, it’s unlikely that all of these wells will be clogged anytime soon. Operators are responsible for plugging oil and gas wells that are no longer needed, but some companies simply choose to walk away or transfer ownership. When no one is legally responsible for a well, it becomes “abandoned”.
Some states in the country have programs to plug these wells, and the Biden administration allocated over $4 billion for abandoned wells last year, Reuters reported. However, this is only a fraction of what would be needed to close the idle wells in the Gulf.
The study authors are working with researchers in the Louisiana Department of Natural Resources to answer questions about how wells affect the environment. “We help these wells estimate their actual methane emissions to do a real climate cost-benefit analysis,” Upton says.
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