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How Far Could the Gulf Oil Slick Spread?

June 3, 2010 at 12:00 AM EST
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As BP attempts to place a containment dome over the leaking oil well, Judy Woodruff talks to two engineering experts about the latest effort to cap the Gulf oil well and concerns over the spread of the larger oil slick.
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JUDY WOODRUFF: Now a closer look at efforts to cap the well and at that computer model we just saw showing how far the oil may flow.

Donald Van Nieuwenhuise is professor of petroleum geoscience at the University of Houston. He spent 20 years in the oil business. And we hope to be joined by Nancy Kinner. She’s an environmental engineer and co-director of the Coastal Response Research Center at the University of New Hampshire.

First to Donald Van Nieuwenhuise.

How — first of all, tell us, how difficult is this latest cut-and-cap effort?

DONALD VAN NIEUWENHUISE, geologist, University of Houston: Well, the overall effort, of course, the cutting part of this effort, they had some difficulty. And thank goodness they were able to shear off and slightly plane down part of the rough cut, so that they can get a good seal.

But this particular effort should work much better than the containment effort did, because they’re going to be able to actually get a slight seal on to the lower marine riser package. And, in the past, they just had a containment dome that was open up to the sea.

And, in this case, they will actually have at least a bit of a seal to try to keep most of the water out. And the biggest issue that they have to worry about right now are the ice crystals that could clog up the pipe.

JUDY WOODRUFF: So, what determines whether this works or not? What’s the key here?

DONALD VAN NIEUWENHUISE: The key will be if they’re able to successfully position it over top the blowout.

As you might imagine, there’s a significant amount of pleasure and flow coming out of that wellhead. And they will need to position this capping device on top of that lower marine riser package. And they will need to stabilize it and clamp it down on to it.

And I think it’s an advantage that they can clamp on to this lower marine riser package, because it will help hold the — if you will, it’s kind of like an upside-down teacup. It will help hold that teacup up — upside down and in place, so that it can capture most of the oil.

JUDY WOODRUFF: So, at this point, Professor, how confident are you that this looks like it’s going to work?

DONALD VAN NIEUWENHUISE: Well, they did have a bit of luck by being able to cut the pipe. And I’m hopeful that they will be able to do it. This has never been done at this depth before, so every step is another experiment essentially.

And I think it’s important to realize that, you know, they’re trying to do everything that they can do, and that this particular effort, because they will be able to handle some of the issues that caused the ice to form in this particular instance, that they are going to have a lot better shot at it.

And once they get the flow rising through the production pipe, they should be able to produce somewhere between 70 percent and 80 percent initially, and my gut feeling is, is that they ought to be able to engineer it to more like 95 percent of the flow.

JUDY WOODRUFF: So, Don Van Nieuwenhuise, you’re saying maybe as much as 95 percent?

DONALD VAN NIEUWENHUISE: That wouldn’t be the initial. And that would be my top-end guess on it.

Actually, they’re going to have some flow coming out of the cap, and the reason that’s actually a good thing is that if, for example, they were producing 105 percent of the oil, they would also be drawing water into the system, which could then cause the risk of having ice formation from the gas clathrates that they call them.

JUDY WOODRUFF: If this works, can this hold for the two months or however long it takes until the relief wells are finished?

DONALD VAN NIEUWENHUISE: I think there’s a good chance that it will.

And one of the problems they could have is, as the pressure is extremely great down at the reservoir — and I know they have been producing some sand — you could have sand that could actually abrade the pipe itself. But, based on what we have seen so far, it didn’t abrade the liner or the — excuse me — the riser where that was crimped.

And, consequently, I don’t think they’re producing that much sand. So, this should hold out for the two months that they need.

JUDY WOODRUFF: All right, I want to turn now to Nancy Kinner at the University of New Hampshire.

I want to ask you, Professor Kinner, about this new model we showed a few minutes ago from the Center for Atmospheric — National Center for Atmospheric Research, essentially showing how a liquid in the Gulf of Mexico with these currents could reach — go around Florida and reach the Atlantic Ocean by the summer.

How realistic is that scenario?

NANCY KINNER, Co-Director, Coastal Response Research Center at the University of New Hampshire: Well, I think you have to look at the model itself and understand a couple of caveats, a couple of things about it.

One thing, as you pointed out, this is just a model looking at if we put a dye, something that actually just moves with the water, and doesn’t degrade at all, where it would go over time.

And that’s not really how the oil will behave. So, what this model does is, it looks at the oil in the top about 60 feet or so of the water column. And it basically does — looks at a set of scenarios about where that water might move.

Now, over those kinds of time periods, many, many days, the oil actually what we call weathers, which means that the oil changes in character. So, some of it evaporates. Some of it actually breaks down in the light. Some of it actually biodegrades. Bacteria over the longer term like that, over many days to weeks, actually start breaking the oil down.

And what happens is — that is very different from what was modeled — is that the oil actually becomes stickier and starts to form what we call tar balls. And you have seen some of those in the pictures of the Gulf.

There are anywhere from very, very tiny, small balls that you could barely see up to about the size of your thumbnail. And so they will travel very differently, as you can imagine, than would just the water itself. So, that’s one thing that we have to keep in mind.

And the second thing is that, when you looked at — at the visual of the model, remember that the color tells you something about the dilution of what’s happening. And, so, this model is basically — when you see those kind of — those yellow, yellowish hues or colors, those are fairly low concentrations of the oil.

So, there — those are two very important things to keep in mind.

JUDY WOODRUFF: And I just want to say, you know, for one, just to look at that picture, it could be fairly alarming, and we should say that the people…

NANCY KINNER: Right.

JUDY WOODRUFF: … who — who put this out at the National Center for Atmospheric Research were careful themselves to say that this is just a scenario, that they don’t — that they’re not saying necessarily that this is what would happen to the oil.

But, based on what you said, could the oil end up any — doing anything like what you see in that — form or that scenario they put together?

NANCY KINNER: Well, I think that it — one has to understand that there’s a lot of oil coming out of the well, and that it is quite likely that some small amount of that oil will get out into the Atlantic Ocean. I mean, I think most — most scientists think that that is going to happen.

However, it probably isn’t going to be large quantities of oil and it certainly isn’t going to be large slicks of oil. In fact, the oil, as it keeps moving, that which is on — in the surface water, that oil starts to, as I mentioned, kind of break up and become what we call streamers or — and then ultimately these tar balls.

So, I think it is quite likely that some small percentage of the oil will get out into the Atlantic. If the oil flow stops, can be stopped down, then I think it will be less and less oil going out there.

JUDY WOODRUFF: Well, we will have many more days to think about that, but it’s helpful to take a look at it right now.

Nancy Kinner, we thank you.

NANCY KINNER: Thank you.

JUDY WOODRUFF: And Don Van Nieuwenhuise — we thank you both for talking with us.

NANCY KINNER: Thanks very much.

DONALD VAN NIEUWENHUISE: Thank you.