Five years after the Obama administration promised to move swiftly to permanently plug unused oil and gas wells in the Gulf of Mexico, even more shafts are lingering for longer periods with only temporary sealing, an investigation by The Associated Press shows.
It is not clear how many incompletely sealed wells may have leaked — they generally are not monitored as carefully as active wells — but they contain fewer barriers to pent-up petroleum and rupture more easily. The threat to the environment increases with time.
In July 2010, during the BP oil spill, the AP reported that the Gulf was littered with more than 27,000 unused wells, including 14 percent left with just temporary seals.
The AP's new analysis of federal data shows that the neglect of long-idle wells has intensified since 2010, despite the federal push after the BP accident:
—Twenty-five percent more wells have now stayed temporarily sealed for more than a year, jumping from 2,855 to 3,576.
—Wells sealed temporarily for more than a year make up 86 percent of all temporarily sealed shafts, up from 78 percent.
—The number of wells equipped with temporary barriers for more than five years has risen from 1,631 to 1,895 — a 16 percent increase.
"I think there are signs of progress, but, my God, we got a long way to go," said Bob Bea, an emeritus engineering professor at the University of California, Berkeley, when told of the AP findings. Bea, who advised the government on safety after the BP spill, said he'd give "a poor grade" to efforts to seal wells since then.
In the aftermath of the BP spill, federal officials rolled out a program to push companies to permanently seal wells "in a timely manner." That effort, known as the "Idle Iron" program, is beset by loopholes that essentially allow companies to delay permanent closure indefinitely, the AP found.
The government allows wells to remain temporarily sealed when companies say they intend to reuse them. However, the rules let oil companies dodge either temporary or permanent sealing on active leases simply by filing plans to make use of the well eventually. Such wells are not considered idle. Other wells without any conceivable use must be plugged after five years, but temporary sealing is then acceptable until the lease expires. Some leases have lasted for almost 70 years.
The AP analysis in May shows that 1,065 wells have been left with temporary sealing for at least a decade, up from 1,009 wells in 2010 — a rise of 6 percent.
Such wells are subject to corrosion and intense pressure at depths down to almost two miles below the water's surface. Shafts penetrate as far as six miles into the seabed.
"The older it is, probably the more attention needs to be given to monitoring and maintaining it," said John Rogers Smith, a retired professor at Louisiana State University who also used to do engineering work for offshore wells in the oil industry. "Are ... people really paying attention to something that's sitting there doing nothing for five-plus years?"
Permanent sealing installs multiple plugs, including one very near the mouth of the well. Permanent closing also cuts off all hardware 15 feet below the seafloor, blocking any ready oil pathway to the water. But these jobs cost more and take more time than temporary sealing, which also entails multiple seals but allows a smaller uppermost plug to be set 1,000 feet down from the mouth of the well. Temporary sealing keeps piping in place that can channel a leak up to the seabed.
Companies often seal wells temporarily to allow time to work up plans to fix a drilling problem or damage from a storm. Some owners, though, temporarily close wells for economic reasons: to wait for higher oil prices or better drilling technology.
Roger Anderson, an oil geophysicist at Columbia University, said some reasons to keep a well temporarily sealed are legitimate. But at a minimum, he said wells in this temporary condition since the 1950s should be permanently sealed, since they were drilled before many improvements in well design.
In mid-May, according to a federal well database, there were three Gulf wells on U.S. leases kept in temporary sealing since the 1950s and another 17 since the 1960s.
Leaks in such wells are likely to occur in small volumes that could easily go unnoticed. But federal reports have for years warned that such releases are harmful to the environment. And state and federal regulators have acknowledged that even drained wells can re-pressurize, and some sealed wells eventually leak.
The BP leak, the worst-ever in offshore U.S. waters, occurred at a well that the company was in the process of temporarily closing. The accident killed 11 workers and spilled up to 172 million gallons of oil. Federal officials defend their well safety efforts since then, and there have more permanent closures. There were 25,928 permanently sealed wells in mid-May, up 10 percent from 23,468 at the end of the BP spill, according to the AP analysis of federal data.
Michael Saucier, who oversees federal efforts to close idle wells, said in a statement that he intends that "wells with no future use be properly abandoned."
"From the data available," he said, "it is evident that we are accomplishing this goal."
Saucier's agency, the U.S. Bureau of Safety and Environmental Enforcement, released data to the AP saying that as of February, only 1,120 wells remained targets of its Idle Iron program to permanently plug wells. There were 3,233 in October 2010 — a two-thirds decrease. The number of oil platforms considered idle has dropped from 617 to 266.
However, wells on active leases can remain temporarily sealed for decades under this program, as long there are plans for reuse.
Asked about the rules, federal regulators suggested that some permanent sealing jobs would be unwise, because cutters and explosives used to fully sever and bury wells may pose danger to nearby active wells. They said unsafe wells can be ordered to undergo permanent sealing if necessary.
Fieldwood Energy LLC and subsidiaries — Fieldwood Energy Offshore LLC and Fieldwood SD Offshore LLC — have 711 temporarily abandoned Gulf wells, more than any other companies, according to the AP analysis. Those wells also include more such wells inactive for over five years than anyone else — 419 — including seven dating to the 1960s.
Mike Dane, a vice president of the private Houston-based Fieldwood Energy, said in a statement that temporary seals act as "vital barriers necessary to ensure a well is safely abandoned," even without permanent abandonment. He acknowledged that it's "generally more practical" to wait for full permanent closure until the associated oil platform is removed.
Oil platforms often remain in place until leases expire. Even then, the rules let companies take another year to fully seal wells.
The pressure on the Gulf is apt to keep increasing. The overall number of wells has increased by 5 percent since 2010: from 50,784 to 53,481. The number of temporarily abandoned wells has risen by 11 percent, from 3,669 to 4,081.