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Posts Tagged ‘BP’

How to Plug an Oil Leak with Corn Starch

February 1, 2011 3 comments

NASA'S Terra Satellite captured this image of the Deepwater Horizon oil slick on May 24, 2010. (Photo: NASA/GSFC)

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One of the biggest, if not THE biggest news story of 2010 was the Deepwater Horizon oil spill. The spill released over 200 million gallons of crude oil into the Gulf of Mexico and is one of the biggest man-made natural disasters in history.

The spill lasted for nearly 3 months due to the high difficulty of plugging the well. One such attempt to plug the leak was the “top-kill” method, which involves releasing a heavy fluid (“mud”) into the well in hopes that it would sink to the bottom and stem the flow of oil. BP’s attempt at this failed, and a paper published online yesterday in Physical Review Letters entitled “Viscoelastic Suppression of Gravity-Driven Counterflow Instability” explains why, and how they could have done better.

So you can imagine the problem like this: you have a well gushing oil upwards. You want to slow down this flow of oil, so you release a dense fluid down into the well and hope it will flow downwards, against the pressure of the oil.

When two different fluids come into contact at different velocities it generates turbulence at the interface. This is called the Kelvin-Helmholtz instability. You have seen it before when you look out onto the ocean or a body of water and the wind creates ripples and small waves on the water. Turbulence is being generated at the interface of the water and the air causing those ripples.

A similar thing happens when oil meets a dense fluid. If the turbulence generated at the interface of the two fluids is high enough to break the “mud” into tiny droplets, then the top-kill method will fail because the mud simply breaks apart and won’t plug the well.

In this paper, the authors demonstrate a fluid which overcomes the Kelvin-Helmholtz instability under conditions similar to those at the site of the Deepwater Horizon spill.

First, however, they theoretically study the effect of using a typical water-based mud in a top kill method for conditions similar to those at Deepwater. What they found was that a typical mud would not have descended quickly enough into the mud to be effective. In other words, the velocity of the oil shooting up the well was much greater than the rate at which the mud would have descended into the oil, resulting in the mud simply being washed out of the well. This would explain why BP’s top-kill attempt had failed.

The authors then tested their own recipe for a mud which may have worked. They introduced a “dilatant polymer with shear-thickening and viscoelastic properties”. What this means is they added a material which would actually get harder under stress (shear-thickening) and resist breaking apart when in contact with the oil. In fact, the force of the oil moving upwards is what would cause it to get harder.

A fluid like this is made of a corn-starch water emulsion. Under high shear stress this fluid gains a “tramponlinelike” behaviour, helping it resist the turbulent flow of the oil.

To test their fluid, they “filled a transparent column 1.6 m tall and 63 mm in internal diameter with a transparent light mineral oil”. They then released their mud into the oil and observed the effects. Using a plunger they simulated the movement of oil over the mud. They found that their corn-starch mixture did not break apart and descended as a coherent “slug”.

The also found that the slug descended at a rate fast enough that it would have overcome the upward velocity of the oil from the Deepwater well. However, they did note that the experiment would have to be repeated at a larger scale to gain a better idea if this would be a useful approach for an actual oil spill.

Beiersdorfer, P., Layne, D., Magee, E., & Katz, J. (2011). Viscoelastic Suppression of Gravity-Driven Counterflow Instability Physical Review Letters, 106 (5) DOI: 10.1103/PhysRevLett.106.058301

Top 10 Quotes of the Year

December 13, 2010 Leave a comment

Its getting near the end of the year. That means Christmas, Hanukkah, and Top 10 lists.

I love top 10 lists. Probably part of the reason I’m still on Team Letterman and not Team Leno.

Here’s the first one I’ve seen so far: The Top 10 Quotes of the Year. Fred Shapiro, associate librarian of Yale University, has released his list of top quotables for the past year, which he has been doing since 2006.

So without further adieu, here is the list. My favourite is #9 since it’s the one that made me want to bang my head against the wall the hardest.

#10. “They should never have put me with that woman. … She was just a sort of bigoted woman who said she used to be Labour.” Gordon Brown, comments about a voter he met while campaigning for British general election, Apr. 28.

#9. “You’re telling me that the separation of church and state is found in the First Amendment?” Christine O’Donnell, Delaware senatorial debate, Oct. 19. (The Associated Press reported the quote: “So you’re telling me that the separation of church and state, the phrase ‘separation of church and state,’ is in the First Amendment?”)

#8. “I’m going to take my talents to South Beach.” LeBron James, television broadcast, July 8.

#7. “We have to pass the (health care) bill so you can find out what is in it.” Nancy Pelosi, speech to National Association of Counties, March 9.

#6. “I hope that’s not where we’re going, but you know, if this Congress keeps going the way it is, people are really looking toward those Second Amendment remedies. They’re saying: My goodness, what can we do to turn this country around?” Sharron Angle, radio interview in January.

#5. “Chi! Chi! Chi! Le! Le! Le! Los mineros de Chile!” Chant at Chilean mine rescue, Oct. 13.

#4. “Don’t retreat. Instead — reload!” Sarah Palin, Tweet, March 23.

#3. “If you touch my junk, I’m gonna have you arrested.” airline passenger John Tyner, remark to Transportation Security Administration worker at San Diego airport, Nov. 13, 2010

#1. (TIE) “I’d like my life back.” Tony Hayward, comment to reporters, May 30.

#1. (TIE) “I’m not a witch.” Christine O’Donnell, television advertisement, Oct. 4.

Yahoo’s Most Searched Terms in 2010

December 1, 2010 Leave a comment

Yahoo! has released its top 10 searches of 2010. The list is:

1. The Gulf of Mexico oil disaster

2. The World Cup soccer tournament

3. Pop singer Miley Cyrus

4. Reality TV star Kim Kardashian

5. Singer Lady Gaga

6. Apple’s iPhone

7. Actress Megan Fox

8. Singer Justin Bieber

9. “American Idol”

10. Singer Britney Spears

Now, should I do my typical geeky, anti-pop culture rant about this? I will try and restrain myself.

But #1 Oil Spill, #2 World Cup, #3 Miley Cyrus?

C’mon people! Have you seen the internet!? There’s way cooler stuff than Miley Cyrus!

Physics of the Vuvuzela: Update!

July 4, 2010 1 comment

In a previous post, I talked about the physics of the vuvuzela. That annoying trumpet at the World Cup which has gotten so much press lately.

I discussed how they work, why they are so loud and why they are so annoying. And why filtering the sound from the TV broadcasts would be very difficult to implement.

But, in the infinite ingenuity of the human race, one New York video producer has found an brilliant and awesome use for the vuvuzela.

BP CEO Tony Hayward

Adam Quirk is apparently raising money to hire 100 vuvuzela players to play out front of BP headquarters in London for an entire day.

The stunt is intended to remind BP that they have some shit to do, and shouldn’t be dragging their feet. The oil spill is now the worst in the history of the Gulf.

This idea with the vuvuzelas is brilliant. They have gotten so much attention lately that this story will surely garner some attention, assuming they can raise enough money. And of course, vuvuzelas are just friggin annoying. So hats off to you Adam Quirk, give those morons what they deserve.