MIAMI — Over the past 15 years, oil companies have drilled deeper and farther into the Gulf of Mexico, taking on new risks in the hunt for new deposits of oil.
Yet industry safeguards to prevent or minimize spills have failed to keep pace with the increased dangers of exploration, despite a series of warnings, malfunctions and near-misses over the years, federal studies and interviews show.
As BP and other oil companies have drilled wells as far as 10,000 feet down in the Gulf, they have continued to use key safety systems that are largely the same as those used in shallower water safety systems that have failed in the past.
And while the consequences of an accident like last month's Deepwater Horizon explosion and leak have increased with the expansion of deep drilling, the oil industry's ability to respond to a catastrophic spill has not.
One federal study from 2004 described the industry's options for stanching a major well leak as "nonexistent."
Nevertheless, the federal agency that oversees offshore drilling, the Minerals Management Service, continued to encourage deepwater exploration, and unlike in some other countries did not demand an extra backup system to avert disaster.
"It hasn't been as much a regulator as a partner," said Marilyn Heiman, a former member of the Exxon Valdez Oil Spill Commission who now is U.S. Arctic program director for the Pew Environment Group.
Environmentalists, who have long warned that the consequences of a rig failure could be catastrophic in the Gulf, see the rig explosion and the ongoing struggles to contain a slick bigger than some states as a nightmare come all too true.
"It's clear where the R&D dollars of the oil industry haven't gone," said Mark Ferrullo, executive director of the advocacy group Environment Florida. "If you look at the solutions they are employing, they're using fire, one of the oldest technologies on the planet, and dispersants, which are more toxic than the oil, and basically a giant thimble (the 100-ton containment dome lowered Friday onto the leak) they had to build from scratch."
Industry leaders conceded as much in a paper presented at a conference seven years ago.
"At times, it appears the industry attitude is that we cannot afford R&D in advance of a defined need," wrote the authors, among them an executive with Transocean, Ltd., the offshore drilling contractor that owned the Deepwater Horizon.
Robert Bea, a professor of civil engineering at the University of California-Berkeley with decades of experience in offshore drilling design and accident investigation, believes the industry at least in the United States has bought too much into its own high-tech hype.
"If you compared us to commercial aviation, to nuclear power, even to chemical refineries, you would find out the likelihood of having these bad things happen is at least a factor of 10, if not 100, higher," he said.
The April 20 blowout on the Deepwater Horizon, which left 11 people missing and presumed dead, is now believed to have been caused by a methane gas bubble that escaped from the well and shot up the drill column.
One thing has been clear from the start: The blowout preventer, a safety device connecting the pipe from the rig to the well on the Gulf floor, failed to seal off the well after the explosion, as designed.
The massive devices, which can stand 50 feet tall, contain a series of valves designed to close around a drill or, in an emergency, trigger rams that will cut through the well pipe and seal it. The one on the BP well, however, either failed to close or only partially closed; submersible robots have not been able to active the rams, despite repeated efforts by BP.
The blowout preventer also was equipped with a "dead man" switch designed to seal the leak even if the rig's power systems fail -- but that failed as well.
Blowout preventers are hardly foolproof: One 1999 study for the Minerals Management Service -- a study the oil industry refused to help fund -- cited more than 20 "safety critical failures," including leaks on pipes that were supposed to be sealed, loss of controls, and a failure to shear a pipe closed.
In another test by federal officials in 2002, half the blowout preventers studied failed in some way, said Bea. "The equipment itself has got a questionable reliability performance record," he said.
After the explosion and spill, BP sent a letter to Transocean, the world's largest offshore drilling contractor with 140 rigs around the globe, asking the company to double-check its blowout preventers to ensure their safety.
Florida Sen. Bill Nelson is leading calls for congressional investigations of both the Gulf spill and the conduct of MMS, a branch of the federal Department of the Interior that oversees the drilling industry.
Nelson has also asked Interior's inspector general to investigate why the MMS in 2003 dropped a proposal to require additional backup systems on Gulf oil rigs to protect against blowouts like the Deepwater Horizon spill, which continues to spew more than 210,000 gallons of oil a day from a well 5,000 feet deep, threatening the coastlines of Louisiana, Mississippi, Alabama and Florida.
MMS officials did not respond to interview requests on Friday.
Yet industry officials have also raised complaints about the blowout preventers. The 2003 report co-authored by Earl Shanks, a Transocean engineer, called blowout preventer failures "common," and said they cost oil companies millions of dollars in down time and delays.
Allison Nyholm, a spokeswoman for the American Petroleum Institute, an industry trade group, said blowout preventers have seen improvements in recent years. Industry insiders say safety has improved even as they have moved into deeper territory, citing one federal study showing a steady decline in blowouts on offshore rigs from 2000 to 2006.
Other experts caution against pointing a finger at a single component, calling total failures of blowout preventors rare.
"It's a proven technology. It's what we have been using for the last 50 years," said Bill Bryant, a professor of oceanography with expertise in petroleum engineering at Texas A&M University.
Yet Nelson and others have questioned why the MMS does not require deep-drilling rigs to have another failsafe -- an acoustic backup system to cut off the gushing well. Acoustic switches, remote controls that use sound pulses to trigger the blowout preventer, are required in Norway, reputed to have the strictest safety standards for offshore drilling, and in Brazil.
As far back as 2000, records show, MMS urged oil companies to add a backup system to its drilling equipment. The agency issued a series of safety notices, most recently in 2009, warning about reliability and other concerns but never wrote regulations demanding backup systems.
In a conference call last week with Wall Street analysts, Transocean's president, Steven Newman, questioned whether an acoustic switch would have made a difference April 20. Newman said there were already backup systems built into the blowout preventer and the switch would simply add another "redundancy."
The 1999 study found that in some blowout preventers, the redundant measures all depended on the same hydraulic line -- meaning a leak in that line could collapse the whole safety system.
These dangers are made more acute in deepwater drilling, where deep ocean currents combine with frigid temperatures and crushing pressures to make dangerous accidents more likely -- and much harder to fix. A 2004 study found the industry had "no guidelines or procedures for blowout containment in ultradeep water."
Regulators' concerns about the potential consequences of a deepwater leak increased in May 2003, when a pipe from a rig in 6,000 feet of water broke in two over a well in the Gulf of Mexico owned by BP. Had the blowout preventer been damaged or failed, the leak would have exceeded the scale of the Exxon Valdez disaster in less than a week, a review later found.
The difficulties in fixing a deepwater well leak have been laid bare by the Deepwater Horizon spill. Adm. Thad Allen, the Coast Guard's highest-ranking officer, who was appointed by the Obama administration to take command of the containment effort, acknowledged from the outset that the options were limited by what he called "the tyranny of depth."
The MSS has bankrolled volumes of research over the years into improved oil containment and proposed added safety measures to deal with deep water accidents -- from backup blowout systems to robotic tractors -- but most of the ideas remain on the shelf.
To contain the gushing Gulf spill, BP has built a massive, four-story dome, hoping to encase the leaking oil and pump it up to a ship.
Even if the containment dome succeeds in corralling the Gulf spill, most experts believe the Deepwater Horizon accident will lead to significant new reforms across the industry, much like the Exxon Valdez disaster in Alaska 21 years before.
"You ask, 'Why in the hell does this happen?' The answer is, we are pushing too fast, too far," said Bea. "I think we got too confident."