Special Reports

BP to try 'top hat' to cap oil spill

BILOXI, Miss. — When the oil spews from the Gulf floor it’s hot, roughly 200 degrees, but as it runs through a busted well riser in 42-degree water it cools rapidly, and the main battle this week for engineers and scientists trying to prevent the BP spill from becoming the worst ecological disaster in history will be against ice crystals.

“The natural gas in it, under pressure, gets cold and it forms hydrates,” said Eric Smith, associate director of the Tulane Energy Institute, “Think of it as water, frozen like a cage around tiny methane balls — ice crystals. The way to get rid of them is to reduce the pressure, change the temperature or inject methanol.”

The scientists and engineers working with BP to put a “tophat” funnel over the largest of two leaks today will be trying all these methods to prevent ice from gumming the works.

Last weekend, a larger, similar setup failed to work. A 40-foot-tall cofferdam was lowered over the leak, but before a pipe could be attached to the top, ice crystals plugged the opening. BP engineers said the mix coming from the busted well apparently had more gas in it than expected.

The smaller tophat funnel, a little larger than a barrel of oil, will already have a drill pipe attached, with warm water being pumped into a sleeve around the smaller pipe and methanol — wood alcohol — being injected to fight the ice.

The Deepwater Horizon disaster is a horse of a different color for the oil industry, environmentalists and the federal government. The problem is, BP CEO Tony Hayward said, “nothing has been tried at 5,000 feet.”

There was obviously no contingency for such a catastrophe, and everything BP and government responders are doing to contain, stop and clean up the leak is being made up as they go along. Officials admit that so far, they are trying to adapt shallow-water and on-land well blowout responses to an unprecedented deepwater gusher — 5,000 feet below the water, under 2,300 psi pressure, where no humans can go.

If the tophat doesn’t work — and perhaps even if it does — BP engineers plan late next week to try a “junk shot,” injecting various debris into the three-chambered valve known as a blowout preventer, in hopes of clogging it.

The debris could contain bits of car tires, golf balls and other odd items. BP Vice President Kent Wells said engineers have tested all sorts of mixtures of items to see what can best cause a clog and “as odd as it sounds, there is some science to it.”

The one method BP officials feel confident will stop the flow of oil is a relief well, drilled at an angle into the existing well, which can then be plugged with concrete. But even with modern deepwater drilling technology, this operation will take three months. And that’s hurrying.

“There’s no way to rush that,” said Ted Bourgoyne, professor emeritus of petroleum engineering at Louisiana State University, “In deep water, it’s a very involved process. That’s fast for that kind of well depth, about as fast as you can do. You don’t want to get any of those people doing that hurt.”

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