BP's Backup Plans: From 'Hot Taps' to 'Junk Shots'

(May 11) -- Try as they might, BP engineers have been unable to stem the torrent of oil gushing by the hundreds of thousands of gallons into the Gulf of Mexico each day following the explosion that sank the Deepwater Horizon offshore drilling rig last month.

Already an environmental, financial and public relations disaster, the situation looks only to be worsening: Today, as inquiry hearings into the catastrophe began on Capitol Hill, an administrator for the U.S. Environmental Protection Agency told CNN that unless the spill is reined in soon, it "has the potential to be worse than anything we've ever seen."

Neither of the two major efforts BP has attempted so far -- using remote-controlled robotic submarines to activate shut-off valves and lowering a giant concrete dome over the oil leak to cap it -- has proved successful.

Now BP is hoping that the third time's a charm: The company is preparing to drop a smaller dome over the leak site later this week. BP is also said to be pursuing several other contingency plans simultaneously. Here are the ones in the works and under consideration.

Relief Wells

Two weeks ago, BP announced that it had begun to drill a relief well a half-mile away from the leak and positioned to intercept it at 13,000 feet below the seabed. The company is also scheduled to begin work on a second relief well later this week. Once completed, the wells would then be filled with tons of cement, with the aim of permanently sealing the leak. But the drilling process, which could take anywhere between two and three months, is not without its own potential for mishaps: Bloomberg Businessweek notes that either relief well could suffer a blowout like the one that caused the Deepwater Horizon explosion, potentially releasing "as much as 240,000 [additional] barrels of oil a day into the ocean ... almost 50 percent more than the company's worst-case estimate for the first well."

Hot Tap

As The Washington Post observes, if the smaller containment dome can't control the leak, BP will be forced to turn to "Plan D: the 'hot tap.' " This would involve cutting part of the riser pipe -- the tube that usually extends from the seabed to the drilling rig, but that was broken in the explosion -- so crews could suck up the oil using a larger pipe and pump assembly, and deliver it to a ship on the surface.

But the riser pipe is not just a single simple tube: It "consists of several sections ... and includes special devices to compensate for any movement," according to the Oil Gas Glossary, making slicing it a tricky endeavor. The difficulty is compounded by the fact that any cut in the riser pipe might unleash a stronger jet of oil into the water.

New Blowout Preventer

Upstream Online reveals that BP is considering installing a new blowout preventer on top of the existing well to try to shut off the flow. The BOP is the large, multivalve device that should have crimped the drill pipe shut before the leak even started, but suffered a mysterious and spectacular failure. The measure would mean shearing off part of the damaged riser pipe, and then lowering a new BOP on top. "However, if it does not work, it could cause the flow from the well to increase," Upstream Online cautions.

Junk Shot

The Times of London reports that the oil company is also mulling the idea of clogging the leak with "a bunch of debris -- shredded-up tires, golf balls and things like that." The plan would be slightly more technically complex, of course, involving a high-pressure pump that would shoot the debris into the defunct BOP and then filling it with cement. This option has been deemed less risky than others, but could still damage the BOP and cause oil to shoot out "at 12 times the current rate," the BBC says. Still, as Newsweek points out, the method "could stop the leak once and for all by the end of next week."

Dispersants

While BP struggles to control the leak, it is also busy deploying dispersants directly into the water surrounding it. A mixture of solvents, surfactants and other compounds, these chemicals "act like dish detergent," breaking up the oil into particles small enough to be diluted by the seawater and degraded by microbes, Chemical and Engineering News explains.

More than 15,600 gallons of the stuff has been injected into the sea, according to Fox 10 TV, even though it has only been tested twice at the present depth (nearly a mile below the surface) and its potential environmental effects remain widely unknown. This has led to some harsh questions about this technique from Gulf Coast fishermen, the National Oceanic and Atmospheric Administration and others. Still, the EPA has given BP permission to continue use, NBC Miami reports.

And if none of these methods turns out to be the silver bullet? In that case, the last, best hope may rest in BP's "hive" mind of engineers, hard at work on even more experimental techniques. It may even lie among the public: USA Today's On Deadline blog is soliciting creative suggestions from its more technically inclined readers.