Since the first offshore platform appeared off Louisiana 85 years ago, the Gulf of Mexico was a vast oil and gas field. But a new study has found that decades of drilling have left more than 14,000 old, disconnected wells at risk of dangerous spills and leaks that could cost more than $30 billion to plug. Non-producing wells that have not been plugged now outnumber active wells in the gulf, the study said.
The researchers also found that in federal waters, nearly 90 percent of old wells were owned at some point in the past by giant oil companies known as “supermajors,” including BP, Shell, Chevron and Exxon. Under federal law, that means those companies will still be responsible for cleanup costs, even if they may have sold the wells in the past, the study authors said.
Why it matters
Oil and gas companies are responsible under federal and state rules for safely shutting down wells that are no longer in operation. But in the boom-and-bust world of oil and gas production, operators often go bankrupt, leaving wells orphaned and disconnected and taxpayers on the hook.
This increases the risk that oil and other pollutants will leak into the ocean and travel ashore, choking wetlands, especially the sensitive salt marshes along the northern Gulf Coast. Wells that are not properly plugged with concrete can also leak significant amounts of methane, a powerful greenhouse gas that contributes to climate change and its increasingly catastrophic consequences.
Orphaned oil and gas wells are a big problem on land as well. “But offshore is a different beast, especially in terms of the costs involved,” said Mark Agerton, an energy economist at the University of California, Davis, who is one of the study’s authors. “Wells are bigger and just a lot more expensive. You can’t just drive a truck up to it.’
A possible solution
The $1 trillion infrastructure bill signed by President Biden in 2021 allocates $4.7 billion to plug orphaned wells on and off land. That’s a significant amount, but nowhere near enough to cover the backlog of orphan wells.
Yet in federal waters, the government can hold previous well owners liable for plugging them even if the current owners default or otherwise fail to meet their cleanup obligations. Eighty-seven percent of the wells under federal jurisdiction were once owned by one of the supermajors, many of which have recently posted record profits.
“So for federal waters, these deep-pocketed companies would be on the hook,” said Dr. Agerton. “There’s someone to go to”
The companies named in the report did not respond to requests for comment.
It makes sense for public funds to prioritize plugging wells in state waters where no such provision exists. Wells in state waters also tend to be in shallower locations, which makes connecting them cheaper. Any pollution from wells closer to shore has a higher chance of washing ashore and wreaking havoc in the coastal environment, so plugging shallower wells is more urgent.
Even as the world begins to transition from coal, oil and gas to renewable energy sources, decades of mining and drilling in nearly every corner of the world, including the oceans, have left behind the need for massive plugging and cleanup efforts.
In the Gulf, abandoned wells, platforms and pipelines are also becoming increasingly vulnerable to the extreme weather associated with global warming. When Hurricane Ida hit the Louisiana coast in August 2021 with winds of nearly 150 miles per hour, it unleashed a oil spills detectable from space.
The most recent analysis focused on offshore drilling, examining data from drilling in the Gulf of Mexico, including those in federal coastal and state waters of Texas, Louisiana and Alabama. It was published in the journal Nature Energy on Monday.