BP Stops Oil Leak, Starts Critical Test

For the first time in 87 days, the most disastrous oil spill in U.S. history may not be getting any worse--at least for now.

BP today succeeded in stopping the catastrophic flow of oil that started on April 20 when the Deepwater Horizon offshore oil rig exploded and caught fire in the Gulf of Mexico, killing 11 workers and rupturing the wellhead of the MC252 well more than a mile below the surface.

Before BP can claim victory in its 3-month struggle to stop the leaking oil, however, it has to complete a critical "integrity test" to make sure the tight-fitting 75-ton cap that workers put in place today can withstand the pressure with all valves closed. And at best, the cap is a temporary solution. For a permanent repair, BP will have to finish drilling the two relief wells and execute the "bottom kill" strategy, using drilling "mud" and cement to seal the well.

The last of three valves, called a choke valve, was closed at 2:25 p.m. CDT this afternoon, which started the clock running on a 48-hour observation period to see whether the cap can continue to hold back the oil.

And that's not the only danger.

With the well capped, pressure in the reservoir of oil beneath the well could push into bedrock and break through the sea floor, creating new leaks. Another risk is that other leaks might develop deep in the well bore, sending oil flowing into the Gulf once again.

How much oil are we talking about? Nobody really knows.

This is one of the deepest oil wells ever drilled and it taps into an oil field of unknown size. There are a lot of variables here.

Testifying before a House subcommittee, BP CEO Tony Hayward estimated that there might be about 2 billion gallons (around 48 million barrels) of recoverable oil in the field. That's a bit shy of the figure BP quoted when it discovered the field, when industry experts estimated its size as 42 billion gallons (1 billion barrels) of recoverable oil.

That term "recoverable oil" is important, because what the industry considers recoverable oil typically constitutes only about 20 percent of the total amount of petroleum in an oil field. If BP's original figure is correct and the ratio holds true for the oil field where BP was drilling, then the site may hold as much as 210 billion gallons (5 billion barrels) of oil. If high pressure causes irreparable leaks in the sea floor, oil could continue to pollute the Gulf for decades. That's the worst-case scenario.

But for now most people--from Gulf Coast residents to professional environmentalists--are cheering what President Barack Obama cautiously called "a positive sign." But even the most optimistic observers know that even if the leak is stopped for good, the oil spill and its effects are far from over. Cleanup and full recovery will take years, quite possibly decades. Some parts of the marine ecosystem and some wildlife populations may never be the same.

"The oil industry argues that this was an isolated event. We agree--research confirms that oil catastrophes are strictly isolated to oil industry operations," said Sierra Club Executive Director Michael Brune in a statement. "We have not yet found oil spills at wind farms, nor have we found evidence of gushers erupting in solar plants or marshlands devastated by business owners retrofitting their buildings. The best way to prevent another oil disaster is to shift away from oil and onto clean energy.

"If this capping of the oil gusher holds, it is a moment for celebration," Brune said. "We must not, however, ever forget the three months during which BP egregiously mishandled its disaster. It is even more important that we remind ourselves that this problem is much bigger than BP. The entire oil industry has been skirting safety regulations and lobbying against clean energy for years. Over and over again we've paid the price."

"It's time to connect the dots," said Erich Pica, president of Friends of the Earth. "The Gulf oil tragedy, the April 5 coal disaster in West Virginia that killed 29 workers, the extraction of tar sands oil in Canada that's causing cancer to fuel U.S. cars, and an escalating climate crisis are all symptoms of the same problem. Fossil fuels are inherently deadly, and it is time for our country to put in place a comprehensive plan to end our use of them."

Also Read:

• BP Removes Cap, Lets Oil Flow, in New Effort to Stop the Leak
• Government Imposes New Deepwater Offshore Drilling Moratorium
• BP Aims to Stop Leaking Oil Well and Falling Stock Price by July 27