Gulf oil spill: Pressure testing begins on BP well

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BP engineers began a critical test of their leaking Gulf of Mexico oil well Wednesday evening in an effort to determine if its pipes were structurally sound enough to allow them to seal off the gushing oil.

The test will measure the pressure inside the well. High-pressure readings for at least 48 hours would indicate that the well casings are relatively undamaged, which would mean that it is safe to leave the well capped from above.

And that, of course, means the incessant gush of oil, which has already despoiled ecosystems, livelihoods and lives, may finally stop, perhaps by the end of the week.

But the test itself is risky business. It requires that the well be sealed off temporarily with a snug, specially constructed cap that was latched onto the top of the well Monday. And much like a thumb in a hole-studded garden hose, the cap could push oil out of any cracks that might exist in the well.

That scenario, in turn, could cause oil to seep upward and begin gushing from the seabed, potentially turning the well site into a ragged crater and exponentially complicating the response to the disaster.
“That is THE worst-case scenario,” said Iraj Ershaghi, a petroleum engineering expert at the University of Southern California. “Nobody has the technology to handle that.”

Late Wednesday, BP reported on its website that it had closed a ram in its capping device, which is similar to a blowout protector, but that it was working to repair a leak on a “choke” line that would be used to seal the well.

BP officials maintained that there was only a remote chance that new oil leaks could cause the sea floor around the wellhead to crater. Kent Wells, BP’s senior vice president, promised that if the test shows very low pressure in the well, a sign that oil could be seeping out underground, the company would move quickly to reopen the gusher and revert to trying to collect as much of the spewing oil as possible.

“We’ll immediately look to open up the well, because that would be a very strong indicator that we don’t have integrity in the well,” Wells said in an afternoon news conference.

Such concerns were a key factor in the federal government’s decision Tuesday to delay the start of the test for 24 hours.

Wells said in a Wednesday morning news briefing that experts wanted to use that time to consider whether leaks, if they existed, were in the shallow or deep parts of the well.

“What we want to do is avoid that oil is being put out in the shallow environment,” Wells said. “There’s always the potential, remote as it might be, that it could breach up to the surface.”

-- Richard Fausset, from Atlanta