JIM LEHRER: After 85 days, oil stopped spilling into the Gulf of Mexico.
"NewsHour" correspondent Kwame Holman begins our coverage.
KWAME HOLMAN: It happened about mid-afternoon in the Gulf. Video from the seabed showed no signs of oil and gas from the fractured wellhead, a sight never seen since the leak began spewing in April.
President Obama cautiously welcomed the news as he returned to the White House from a day trip to Michigan.
U.S. PRESIDENT BARACK OBAMA: I think it is a positive sign. We are still in the testing phase. I will have more to say about it tomorrow.
KWAME HOLMAN: BP made the announcement after their crews closed a series of valves on a newly installed 75-ton cap. The operation went ahead once robotic submarines repaired an overnight leak in a so-called choke line attached to one of the valves.
In New Orleans, retired Coast Guard Admiral Thad Allen said engineers will watch for the two days to see if the well withstands the increased pressure without springing new leaks.
ADMIRAL THAD ALLEN (RET.), national incident commander: Once we're convinced, we've done no pressure in the wellbore, and it can withstand the pressure after another seismic run, after that 48 hours, we can certainly consider shutting in the well, that's always a possibility, and of course, we would like to do that.
KWAME HOLMAN: Even if all goes perfectly, the massive cap is not considered a permanent solution. BP still plans to complete drilling on a relief well to shoot mud and cement into the leaking well and block it off for good.
JIM LEHRER: A short time ago, Thad Allen said in a written statement that he was encouraged by this development, but this isn't over.
And now to Joel Achenbach of The Washington Post. He's been covering this oil spill story for several weeks.
JOEL ACHENBACH, The Washington Post: Great to be here.
JIM LEHRER: So, as we speak right now, there finally is no oil going out into the water of the Gulf of Mexico?
JOEL ACHENBACH: Something went right.
You know, this has been an incredibly difficult process just for all of us to watch. I mean, this gusher, this black plume of oil, has been a fixture on TV. I know people who have told me they have had nightmares about it. And at least for today, it's gone. I mean, the gusher is gone. The plume just disappeared when they closed that choke line about -- it was at 3:25 p.m. Eastern time today, 2:25 Central, that they shut it down. Now we wait to see what the pressures show.
JIM LEHRER: And the pressure could -- that's why we're still not out of the woods, right? The pressure could, what, cause leaks further down the pipe somewhere, I mean, the line?
JOEL ACHENBACH: Lots of possibilities.
Now, the worst-case scenario is kablooey, OK, that, when you close the well, the pressure builds. And you can just imagine that the casing of this well down below the Gulf floor may be damaged. And so you could have a further kind of a lateral blowout into the rock formation.
Then you could have a situation of sort of cratering, of erosion, of gas and oil surging up in multiple leaks around the blowout preventer. Now, that, however, is not the most likely scenario. And there is no sign that that has happened.
The other possibility is -- and The Washington Post today is reporting -- I talked to one of the top scientists -- the other possibility is the pressure readings could be ambiguous. It is not what you want to see. It's not terrible. You have to sit there and figure out, well, what's going on here?
They may reopen it out of an abundance of caution, reopen the well in a couple of days. And that's not the worst-case scenario, though, because they have got more ways of capturing the oil now with this new stack on top of the well.
JIM LEHRER: So, to read the pressure, they want the pressure to be strong so that shows that there is no leaks further down; is that correct?
JOEL ACHENBACH: That's precisely correct.
If the -- and I will throw a couple of numbers out here.
JIM LEHRER: Sure.
JOEL ACHENBACH: I'm not an engineer. But what we have been told is, if the pressure rises to, say, 8,000 PSI, pounds per square inch, and holds there steady, that's good.
If it doesn't get up above 6,000, that could mean that the oil and gas are leaking from the sides of the well, that they are escaping somewhere, and that the well has lost its integrity. That's why they call this an integrity test.
What I was told was that the most recent numbers that -- the gentleman I spoke to who was there in the room this afternoon, was he saw pressure readings around six 6,700 PSI, which is in an ambiguous range. And so they going to do a lot of analysis of that. It does -- it's not going to be an easy decision about what to do.
JIM LEHRER: Sixty-seven hundred could mean that there is a small leak somewhere. It's possible, right? That's why it is ambiguous?
JOEL ACHENBACH: You know, it would be easy if it rose to the number you wanted and held there. But it's sort of like everything with this whole Deepwater Horizon well -- or it's really called the Macondo well. Nothing has gone quite according to plan.
But you have to give the engineers credit that they have done several things here that were very complicated in the deep sea. This is a mile below the surface. They are doing everything with robotic submersibles, you know, using the robotic claws. They are -- they had to take off the old top of the well, the sort of jagged chimney that they had in place there. They removed the old top hat.
They put a whole new complex, this 75-ton, three-ram capping stack, they call it, put that on the well. They last night had a leak in part of that new stack. They had to take this choke valve back to the surface. Then they had to replace it with a new one. They still had a problem, brought it back up, sent it back down again. Finally, today, this afternoon, they got the well shut in.
JIM LEHRER: And the point you make, it's hard for people to focus on this, that this is being done a mile down there, and with robotics. And here somebody is working something and turned something today that stopped the -- stopped the oil from spewing, right?
I mean, literally, somebody -- what are they looking at? They're looking at TV monitors and see things?
JOEL ACHENBACH: Yes. They -- these technicians are on ships right above the well site, OK? And I actually was on a rig a couple of weeks ago. And I was in the little submersible shack where the technician is sitting in there, and he is joysticking the robot down there on the seafloor.
It's really -- they're very good at this.
JIM LEHRER: Sure.
JOEL ACHENBACH: They can pick up, you know, a wrench using these robots. And they can manipulate a lot of the technology.
I'm sure it takes many years to master this. It's a lot of pressure they are under. But some -- what happened is, they just kept turning and turning and turning the choke valve. And, as they turned it, the valve closes. And, eventually, this three-inch pipe -- all the flow of the well was coming up this last three inch pipe, and they shut it down.
JIM LEHRER: And while that's being done, of course, somebody else is looking to see what the pressure is, see if something is leaking, or see if something is blowing up.
JOEL ACHENBACH: Right.
JIM LEHRER: It must -- the drama involved for these people must be extraordinary.
JOEL ACHENBACH: Well, yes.
I mean, this is -- you know, this is their Apollo 13 moment, in a sense. And we, unfortunately, have limited access to what is going on in the war room. I was there a couple of weeks ago, but just briefly.
JIM LEHRER: Sure.
JOEL ACHENBACH: I was told there was about 25 people in the room. When it succeeded and shut off the well, there was some clapping and handshakes and backslaps.
But they have been, I think, you know, burned by this well before. And so no one is running around popping champagne. This test will last officially two days, 48 hours. Every six hours, they will analyze it to decide, you know, do we want to keep going? What do we want to do?
And when it's over, they will make a decision. Do we want to open the well back up again? I don't think anyone should be shocked if they open the well back up again. And I...
JIM LEHRER: Why would they open it up -- why would they open it up again, Joel?
JOEL ACHENBACH: It's a great question. Because, although for two days -- let's say that all goes perfectly and for two days there's no more, you know, eruptions, there's no more leaks.
I think there's some concern, though, that three, four, five, six, seven days, you could still have a problem, in other words, that if some of this stuff is leaking down there, that the situation could evolve and get worse, I mean, maybe not suddenly, but maybe gradually.
JIM LEHRER: Yes.
JOEL ACHENBACH: And, so, given that they have this better cap on the well, and they have the ability now to collect it, potentially, collect the oil, with four different ships at the surface, two lines coming from the old blowout preventer, two lines from this new capping stack, they could collect, they say, up to 80,000 barrels a day, which is probably more than the well has.
And it wouldn't be bad to know exactly how much this well has been producing. You know, this is something we have talked about for months now. You know, how much oil is there? If you produced all of it, you would know.
JIM LEHRER: Sure. I got you.
Hey, Joel, thanks a lot for updating us. And we will see what happens.
JOEL ACHENBACH: Great. Thank you.
JIM LEHRER: Hey, thank you, Joel.