The calls for action follow an Associated Press investigation that found federal regulators do not typically inspect plugging of these offshore wells or monitor for leaks afterward. Yet tens of thousands of oil and gas wells are improperly plugged on land, and abandoned wells have sometimes leaked offshore too, state and federal regulators acknowledge.
Melanie Duchin, a spokeswoman with Greenpeace, said she was "shell-shocked" by the AP report and upset that government wasn't "doing a thing to make sure they weren't leaking."
Of 50,000 wells drilled over the past six decades in the Gulf, 23,500 have been permanently abandoned. Another 3,500 are classified by federal regulators as "temporarily abandoned," but some have been left that way since the 1950s, without the full safeguards of permanent abandonment.
Petroleum engineers say that even in properly sealed wells, the cement plugs can fail over the decades and the metal casing that lines the wells can rust. Even depleted production wells can repressurize over time and spill oil if their sealings fail.
Regulators at the Minerals Management Service — recently renamed the Bureau of Ocean Energy Management, Regulation and Enforcement — have routinely been accepting industry reports on well closures without inspecting the work. And no one — in industry or government — has been conducting checks on wells that have been abandoned for years.
In its investigation, the AP found a series of warnings. For instance, the General Accountability Office, which investigates for Congress, warned in 1994 that leaks from offshore abandoned wells could cause an "environmental disaster." The report stated: "MMS does not have an overall inspection strategy for targeting its limited resources to ensuring that wells are properly plugged and abandoned."
The GAO report suggested MMS set up an inspection program, but the agency never did.
According to a 2001 study commissioned by MMS, agency officials were "concerned that some abandoned oil wells in the Gulf may be leaking crude oil." But nothing came of that warning.
The oil that has been gushing from a BP PLC well since an exploratory oil rig exploded April 20 is an uncomfortable reminder of the potential for leaking at abandoned wells. The well was being prepared for temporary abandonment when it blew out, setting off one of the worst environmental disasters in U.S. history.
Wells are abandoned temporarily for a variety of reasons. In the case of the BP spill, the well was being capped until a later production phase. Oil companies also may temporarily abandon wells as they re-evaluate their potential or develop a plan to overcome a drilling problem or damage from a storm. Some owners temporarily abandon wells to await a rise in oil prices.
Regulations for temporarily abandoned wells require oil companies to present plans to reuse or permanently plug such wells within a year — and then an annual review — though the AP found those rules are used to allow wells to remain "temporarily" abandoned forever.
Sen. Mark Udall, D-Colo., sent a letter Wednesday to Interior Secretary Ken Salazar asking whether regulators have authority to do inspections of abandoned wells. He said regulators may ultimately need to check industry paperwork more carefully or inspect the work itself.
"We can't afford the leak that's now occurring. We certainly couldn't afford additional leaks in the future," Udall said.
He added that there's generally been a trust of industry, "but I think this is a case where we ought to trust — but we ought to verify."
Environmental activists called for the government to study the extent of leaking, conduct inspections and monitor these wells over the years.
Melinda Pierce, deputy director of national campaigns for the Sierra Club, said the AP investigation shows that the government must do more to prevent another oil disaster.
"From exploration to drilling to the sealing of abandoned wells, the government must step up safety inspections and oversight to ensure that oil companies don't cut corners that could put our marine resources and coastal economies at risk," she said.
Derb Carter, a director with the Southern Environmental Law Center, said government inaction on abandoned wells is "not unlike the way we dealt with hazardous waste years ago where we just buried it somewhere and didn't think about it."
Elgie Holstein, the senior director of strategic planning for the Environmental Defense Fund's land, water and wildlife program, said "it certainly makes sense" for the government to periodically inspect abandoned wells to ensure that they have been properly plugged. Holstein is a former U.S. Energy Department official during the Clinton administration who was on President Obama's transition team.
After repeated requests, federal regulators acknowledged Tuesday that some abandoned wells have leaked in the past. However, a government petroleum engineer, Eric Kazanis, told the AP that abandoned wells aren't considered a risk and aren't "supposed to leak."
Oil companies say they plug correctly, and that seals on properly plugged wells should last virtually forever.
Greg Rosenstein, a vice president at Superior Energy Services, a New Orleans company that specializes in this work for offshore wells, maintained that properly plugged wells "do not normally degrade."
When pressed, though, he acknowledged: "There have been a few occasions where wells that have been plugged have to be entered and re-plugged."
The AP National Investigative Team can be reached at investigate(at)ap.org