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Stopping the gulf oil spill: The slowest method is the surest

Day after day, news keeps breaking about the latest, exotic, long-shot technique to stop the leak that is spewing more than 200,000 gallons of oil into the Gulf of Mexico each day. Tools for the job include underwater robots, golf balls, shredded tires, knotted pieces of rope, a four-story concrete dome and a smaller one dubbed "top hat."

All this sounds so outlandish that comedian Andy Borowitz suggested using a million rolls of Bounty paper towels.

Experts say there is a likely solution. But it happens to be the slowest.

It would work like this: Get a drill to the mile-deep sea floor. Bore a hole two miles deeper, all the way back to the reservoir of oil that BP tapped into originally. Steer the drill so precisely that it pokes into a 7-inch-wide pipe carrying the leaking oil. Shoot cement into the pipe to seal it off.

As complicated as that sounds, experts say that option has the best chance. BP already has begun drilling a relief well and plans to drill a second as well. It could take three months.

"You know the kill well, or relief well, is going to work, probably — there's like a 99 percent chance that will work," said Don Van Nieuwenhuise, who teaches petroleum geology at the University of Houston.

The other methods would be preferable because they're quicker. But they are far less sure because none has been tried in a mile-deep sea, where temperatures hover around 40 degrees and water pressure is crushing.

"Other things that they're trying are not nearly as battle-tested as the relief well," said David Mica of the Florida Petroleum Council.

Here is a look at the options.

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Riser insertion tube

WHAT IT IS: The newest plan, announced by BP on Thursday, is to insert a 6-inch tube into a leaking 21-inch pipe on the Gulf floor.

WHY IT MIGHT WORK: The tube would be placed right into the gushing oil that is causing so much trouble. It would suck up the oil and carry it 5,000 feet up a ship waiting on the surface of the Gulf.

WHY IT MIGHT NOT WORK: In the mile-deep Gulf, icy crystals could form and clog the line. And oil could continue leaking at the point of insertion.

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Relief well

WHAT IT IS: An attempt to seal off the pipe that carries the leaking oil.

WHY IT MIGHT WORK: Relief wells have a track record and have been used many times in many locations. The drilling can take months but it is precise. The idea is to drill deep and cut off the flow of oil at or near its source.

"We know that will work and that unfortunately just happens to be the one that will take the longest to execute," said BP spokesman Ray Dempsey, currently based in St. Petersburg. He said BP is working on several other options simultaneously, to have the best chance of shutting down the spill as soon as possible.

But how can you drill thousands of feet beneath the sea floor and pinpoint a 7-inch diameter pipe? Among other things, magnetometers on the drill can detect when it is getting close to the steel pipe said Don Van Nieuwenhuise, who teaches petroleum geology at the University of Houston. He once worked on a project off the Louisiana coast that also required digging a relief well to the same size pipe.

WHY IT MIGHT NOT: Nothing this complex is 100 percent. Also, when the drill approaches the pipe, sometimes "the last couple feet of rock will break through," particularly if the gushing oil has created an area of low pressure, said Ted Bourgoyne, professor emeritus of petroleum engineering at Louisiana State University. That means there has to be plenty of the sealing material that can shoot into the pipe immediately.

BP has begun drilling a relief well and hopes to move a new rig in place so it can begin drilling a second one simultaneously, just in case one fails.

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Containment dome

WHAT IT IS: A box the size of a small building. BP built one and lowered it over the leak on Saturday.

WHY IT MIGHT HAVE WORKED: It sounds simple enough: The box would have fit over the gushing oil, and then pumped the oil through a pipe all the way to a ship on the surface of the Gulf of Mexico. Kind of like an upside-down funnel.

WHY IT DIDN'T WORK: The intense cold and high pressure of the mile-deep Gulf water, along with the flowing oil, cause chemical reactions. These forces — and not just the temperature — create crystals that could be called "methane ice." All those frozen crystals clogged things up, so the oil could not be pumped up through the pipe.

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Top hat

WHAT IT IS: A smaller, rounder dome, about 4 feet in diameter.

WHY IT MIGHT WORK: It's the same concept as the containment dome, only smaller. In this device, BP will pump in hot water and a solvent to act as a kind of antifreeze, hopefully preventing the icy crystals from blocking the oil here too. This way, oil could flow up the pipe.

WHY IT MIGHT NOT: As BP said in a news release this week, "such a system has never been used in water depths of 5,000 feet and its successful operation is not certain."

Also, it's worth noting that if you pump hundreds of thousands of gallons of oil up to the surface of the Gulf of Mexico, that implies there's a ship up there to take in the oil. These ships could be forced to disperse in a bad storm, which would complicate matters.

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Junk shot

WHAT IT IS: An attempt to clog up the "blow-out preventer." The blow-out preventer acts like a shutdown valve to stop oil from gushing out of an oil reservoir that has been tapped. Obviously, this blow-out preventer failed, and the finger-pointing over why intensified in Congressional hearings this week.

WHY IT MIGHT WORK: BP believes it may be possible to get this device to shut down by clogging it, after shooting in such material as golf balls, knotted rope or shredded tires. Sounds strange, but these materials have been used before, and they are the right size to plug up different parts of the preventer. After that, "drilling mud" and cement would be used to seal it up permanently.

WHY IT MIGHT NOT: The extreme conditions, plus the force of the oil gushing through, make it a technical challenge.

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ANOTHER WORRY: in some of these methods, there also is a danger of widening the leak and making it worse.

"They are concerned that they might cause a bigger leak in the process," said Gerald Graham, president of Worldocean Consulting, a Canadian company specializing in marine oil spill prevention and response planning. "It could exacerbate the problem."

Times researcher Will Gorham and staff writer Craig Pittman contributed to this report, which also contains information from the Associated Press.

Stopping the gulf oil spill: The slowest method is the surest 05/13/10 [Last modified: Friday, May 14, 2010 8:04am]
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