BP, scientists try to make sense of well puzzle

[flamingdem]

http://www.google.com/hostednews/ap/article/ALeqM5gIXWYBTpLtSayJtg41LKXpxSxVPAD9H0FA681

BP, scientists try to make sense of well puzzle

By VICKI SMITH, HOLBROOK MOHR and HARRY R. WEBER (AP) – 21 minutes ago

NEW ORLEANS — In a nail-biting day across the Gulf Coast, engineers struggled to make sense of puzzling pressure readings from the bottom of the sea Friday to determine whether BP's capped oil well was holding tight. Halfway through a critical 48-hour window, the signs were promising but far from conclusive.

Kent Wells, a BP PLC vice president, said on an evening conference call that engineers had found no indication that the well has started leaking underground.

"No news is good news, I guess that's how I'd say it," Wells said.

Engineers are keeping watch over the well for a two-day period in a scientific, round-the-clock vigil to see if the well's temporary cap is strong enough to hold back the oil, or if there are leaks either in the well itself or the sea floor. One mysterious development was that the pressure readings were not rising as high as expected, said retired Coast Guard Adm. Thad Allen, the government's point man on the crisis.

Allen said two possible reasons were being debated by scientists: The reservoir that is the source of the oil could be running lower three months into the spill. Or there could be an undiscovered leak somewhere down in the well. Allen ordered further study but remained confident.

"This is generally good news," he said. But he cautioned, "We need to be careful not to do any harm or create a situation that cannot be reversed."

He said the testing would go on into the night, at which point BP may decide whether to reopen the cap and allow some oil to spill into the sea again.

Throughout the day, no one was declaring victory — or failure. President Barack Obama cautioned the public "not to get too far ahead of ourselves," warning of the danger of new leaks "that could be even more catastrophic."

Even if the cap passes the test, more uncertainties lie ahead: Where will the oil already spilled go? How long will it take to clean up the coast? What will happen to the region's fishermen? And will life on the Gulf Coast ever be the same again?

"I'm happy the well is shut off, that there's a light at the end of the tunnel," said Tony Kennon, mayor of hard-hit Orange Beach, Ala. But "I'm watching people moving away, people losing their jobs, everything they've got. How can I be that happy when that's happening to my neighbor?"

On Thursday, BP closed the vents on the new, tight-fitting cap and finally stopped crude from spewing into the Gulf of Mexico for the first time since the April 20 oil-rig explosion that killed 11 workers and unleashed the spill 5,000 feet down.

With the cap working like a giant cork to keep the oil inside the well, scientists kept watch on screens at sea and at BP's Houston headquarters, in case the buildup of pressure underground caused new leaks in the well pipe and in the surrounding bedrock that could make the disaster even worse.

Pressure readings after 24 hours were about 6,700 pounds per square inch and rising slowly, Allen said, below the 7,500 psi that would clearly show the well was not leaking. He said pressure continued to rise between 2 and 10 psi per hour. A low pressure reading, or a falling one, could mean the oil is escaping.

But Allen he said a seismic probe of the surrounding sea floor found no sign of a leak in the ground.

Benton F. Baugh, president of Radoil Inc. in Houston and a National Academy of Engineering member who specializes in underwater oil operations, warned that the pressure readings could mean that an underground blowout could occur. He said the oil coming up the well may be leaking out underground and entering a geological pocket that might not be able to hold it.

But Roger N. Anderson, a professor of marine geology and geophysics at Columbia University, said the oil pressure might be rising slowly not because of a leak, but because of some kind of blockage in the well.

"If it's rising slowly, that means the pipe's integrity's still there. It's just getting around obstacles," he said. He added that "any increase in pressure is good, not bad."

The cap is designed to prevent oil from spilling into the Gulf, either by keeping it bottled up in the well, or by capturing it and piping it to ships on the surface. It is not yet clear which way the cap will be used if it passes the pressure test.

Either way, the cap is a temporary measure until a relief well can be completed and mud and cement can be pumped into the broken well deep underground to seal it more securely than the cap. The first of the two relief wells being drilled could be done by late July or August.

In a positive sign, work on the relief wells resumed Friday. The project had been suspended earlier this week for fear that the capping of the well could interfere with it.................. MORE

[DCBob]

1. I think the resevoir is partially depleted...

Its been gushing for months..

[DURHAM D]

2. The gas pressure may be lower but -

I doubt the amount of oil is depleted enough to matter.

[DCBob]

4. How would you know? Nobody knows what the real rate of flow has been..

Cleary its been high and going nearly full blast for 3 months.. thats an awful lot of oil. Of cousre its not fully depleted but even a partial depletion could explain the lower pressures. If there is a leak somewhere why hasnt it been detected?

[DURHAM D]

6. That is exactly what they are trying to figure out right now.

Testing for a down hole break in the casing is difficult - esp. if the gas/oil moves into or creates an outlet into another area that can serve as a reservoir.

[DCBob]

10. Yeah, its possible the oil could be moving into adjacent cracks or crevices but..

the fact nothing yet has been detected is a good sign. I still think its a partial depletion situation causing the lower than expected pressure. I guess we will know fairly soon.

[flamingdem]

3. A guest on Olberman said BP moved the goalpost today from 9000 to 7500

psi .... so that their current number looks better .. he implied

[Poll_Blind]

5. It also lowballs the flow rate which saves them money on volume-of-spill penalties.

PB

[jaxx]

7. Good article, thanks.

I missed the report and was interested in what they have to say. I am leaning towards wishing they would go ahead with capture to the Helix Producer and the Discover Enterprise and the Q400. It would still keep the leaking stopped but put less pressure on the well structure. Looks still like mid August before they can kill the well.

edit to fix a word

[Canuckistanian]

8. It's good to see ENGINEERS in charge of the wellhead now

Thanks for the post.

[jberryhill]

9. Amen to that

If anything good can come of any of this, I hope that engineers in general are restored to authority over engineering decisions in engineering companies.