One (short!) year ago today, BP’s Deepwater Horizon oil drilling rig exploded 42 miles off the coast of Louisiana. Eleven families lost loved ones on that day, but the social, economic, and environmental damage had only begun.
Courtesy U.S. Coast Gaurd
By April 22, 2010 the $560 million rig sunk, leaving oil spewing from the seabed into the Gulf of Mexico. On the 29th, the state of Louisiana declared a state of emergency due to the threat posed to natural resources, and U.S. President Barack Obama stated that BP was responsible for the cleanup.
Hopeful in those first days, remote underwater vehicles were sent to activate the blowout preventer, but the effort failed. In the following weeks that turned into months, controlled burns, booms, skimmers, and dispersants were used to cleanup oil as efforts to stop the oil flow were underway. The Justice Department launched a criminal and civil investigation, a moratorium on oil drilling was enacted and later rescinded, and the no-fishing zone grew to 37% of American Gulf waters. After 5 months, 8 days, and roughly 5 million barrels of spilled oil, a pressure test finally determined that a relief well had successfully stopped the oil flow. The spill was the world’s largest accidental release of oil into a marine environment.
Courtesy Daniel Christensen
I know you've probably moved on from the BP oil spill to bigger and better things, like Charlie Sheen. But it's worth resurrecting old news for this: oobleck could have succeeded where drilling mud had an epic fail. A researcher at Washington University in St. Louis, MO, came up with the idea to use oobleck because it doesn't behave like a normal liquid--that is, it flows like a liquid if you pour slowly, but behaves like a solid if you apply force to it or try to move it quickly.
This quirky, non-newtonian fluid would have been a big asset to BP's top kill strategy, because the oil's own force would have caused the oobleck to behave like a solid and plug the well, whereas the oil broke up the drilling mud they used and dispersed it. The challenge lies in getting the oobleck quickly into the well without triggering its solid-like behavior too soon.
Have you ever played with oobleck here at Science Museum of Minnesota or elsewhere? It's pretty great stuff, and you can make your own! Who'da thunk it could actually be useful?
Courtesy Lucas Vieira MoreinaFive months after the deadly accident that spilled five million barrels of oil into the Gulf of Mexico, the Macondo well of the Deepwater oil spill has been declared “dead.”
It’s like when that rabid dog got into your house, and, after a tense struggle, your dad finally pinned its neck under his foot, and, with an Arnold-esque quip like “Bad dog,” sent a 9 mm bullet into the still-thrashing animal’s brain. And then one more, for good measure.
It’s like that, except your house would have to be like a large, deep body of water. And the rabid dog would also have been uncontrollably vomiting flammable poison everywhere. And your dad wouldn’t really have shot it so much as drilled a couple of holes beneath its head, and then pumped it full of cement. And it was your dad’s fault that it started puking like crazy in the first place, because he was really excited to sell more rabid dog vomit to you. (Because who doesn’t love that stuff?)
In any case, the dog/well has been put down with extreme prejudice. Cement has been injected into the oil well through the intersecting relief wells, and the hardened cap has been pressure tested. The well seems to present “no continuing threat to the Gulf of Mexico.”
That’s a good thing, obviously, but unfortunately it’s not the end of this human and environmental tragedy. Before the leaking well was finally capped, about 210 million gallons of oil leaked into the Gulf, some of it floating into slicks on the surface, some of it lurking in thick plumes deep in the Gulf. How the unrecovered oil will affect the Gulf’s ecosystems and its human population remains to be seen, and determining the extent of BP’s financial responsibility to the region’s inhabitants will likely be a lengthy and difficult process.
Still, though: Bad dog. Blam. That’s something, right?
Cleaning up oil spills costs big money. BP says the Gulf cleanup cost is $8 Billion. Hoping that next time we can do it better, faster, and cheaper, Wendy Schmidt has offered $1.4 Million in prizes to inspire a new generation of innovative solutions.
A $1 Million Prize will be awarded to the team that demonstrates the ability to recover oil on the sea surface at the highest oil recovery rate (ORR) and the highest Recovery Efficiency (RE).
If you are interested click here for the competition rules.
MIT may have a jump on the competition with their Seaswarm project. Last week they showed off what looked like a solar powered treadmill that lapped up spilled oil. Using GPS and wireless communication, a swarm of these devices autonomously coordinate their movements.
"We envisioned something that would move as a rolling carpet along the water and seamlessly absorb a surface spill," said MIT researcher Assaf Biderman. "This led to the design of a novel marine vehicle -- a simple and lightweight conveyor belt that rolls on the surface of the ocean, adjusting to the waves." Computerworld
They estimate that 5000 of their robotic sea-swarm vehicles could clean up a Gulf sized spill in a month.
Legal representation from British Petroleum and the U.S. Federal Government have barred university scientists at several major southern institutions from collecting samples on the Gulf Coast. In order for these researchers to have permission to conduct studies in that area, they must sign a document which allows lawyers from both B.P. and the Federal Government to have access and control over their findings. Scientists are outraged and call it a violation of free speech and an insult to the peer-reviewed process.
For more information on this controversy, go to: http://www.npr.org/templates/story/story.php?storyId=129304546
Since the Deepwater Horizon oil rig exploded on April 20th of this year, approximately 4.9 million barrels of oil have flowed into the waters of the Gulf of Mexico. In the intervening months, BP added 1.8 million gallons of petroleum-containing chemical dispersant to the oily waters. It is not yet clear what the effects of such a mix will be.
When oil is spilling into water, as it did for 114 days from BP’s blown out Macondo well, there are three options available for clearing it: skimming, burning, and dispersing. Skimming the oil is the safest and least environmentally-damaging option, but the skimmer equipment is expensive and slow to deploy. Burning can effectively remove oil from the water, but the process pollutes the air and sends a lot of heavy residue to the sea floor. For this spill, BP decided to rely substantially upon the use of chemical dispersants.
Chemical dispersants do not themselves remove oil from water, but bacteria that naturally live within the Gulf of Mexico do. The trouble is that the highly cohesive properties of oil mean that large slicks like this one in the Gulf present very little molecular surface area upon which the microbes can work. Thus, the dispersants, which work a bit like dish detergent, are used to break up the oil into smaller droplets and make it easier for bacteria to degrade.
In an attempt to keep oil off of Florida beaches and out of deltaic wetlands (and, some would say, out of the public eye), dispersants were applied in vast quantities and in unprecedented ways during the Gulf Coast cleanup effort. Not only was it sprayed from planes onto the surface of oil slicks, as is the traditional application, it was pumped 1.5 km below the ocean surface into the oil plume flowing from the broken wellhead. More than four million liters of dispersants were applied to surface waters offshore and 2.5 million at the site of the leak.
The long-term implications of this unprecedented use of dispersants are not known. The oil is now spread more widely than it would have been without the use of dispersants and the smaller particles are located throughout the water column. The worry is that the small, diffuse particles will be more easily taken up by marine organisms. "By breaking up oil slicks, you might reduce the number of acutely oiled pelicans and sea turtles," Doug Rader, chief ocean scientist for Environmental Defense Fund told Rolling Stone Magazine. But, adds Melanie Driscoll, a bird-conservation director with the National Audubon Society, “Are these birds better off in the long run than the heavily oiled birds? We don't know. We don't know yet about their survival rate weeks or months from now, or about their reproductive capacity in the future. Frankly, there are just a huge number of unknowns here – and that's what concerns me."
Courtesy US Fish & Wildlife Service
There is also concern that bacterial degradation of the dispersed oil is leaving behind large swaths of de-oxygenated water that is inhospitable to marine life. Larry McKinney, executive director of the Harte Research Institute of Gulf of Mexico Studies at Texas A & M University told Discovery News that the spill may have increased the size of the so-called “dead zone” of oxygen-starved water in the Gulf. The zone, which is caused by agricultural runoff flowing through the Mississippi River, is the largest it has been in twenty-five years. McKinney believes that increased microbial oil metabolism is the culprit.
The dispersants that were used on the Macondo BP oil spill were developed by Exxon in the 1970s and are sold under the name Corexit. By volume, Corexit 9500 is largely composed of petroleum distillates, solvents known to be animal carcinogens. But, as marine biologist Jane Lubchenco, director of the National Oceanic and Atmospheric Administration, expressed at a press conference on May 12, the use of these dispersants was viewed as “a trade-off decision to lessen the overall environmental impact.”
What exactly that trade-off will be is unclear. In the wake of its widespread use, questions developed about the toxicity of Corexit and other dispersants in combination with oil. Last week, the EPA released a study on the acute toxicity of dispersants alone, oil alone, and dispersants in combination with oil. The results of the study suggest that the toxicity of the dispersant-oil mixture is similar to that of oil alone and is more toxic than dispersant alone; the long-term health effects of the dispersant breakdown products however are entirely unknown.
4.9 million barrels of oil, where did it go?
“It’s becoming a very elusive bunch of oil for us to find” – National Incident Commander Thad Allen
The federal government released a report last Wednesday claiming that about 75% of the more than 4.9 million barrels of oil spewed from BP’s blown out Macondo well has “evaporated or otherwise been contained.”
After reading which I thought: “...?..”
Really? Where did the oil go? The oil really evaporated?
The chart suggests that about one quarter of the oil that spilled from the well remains in the water, on shore, or in sand and sediments. One quarter of the oil is said to have evaporated or dissolved in the water, and the rest has been dispersed or collected (more on dispersion later).
OK…but, again, really evaporated? And why hasn’t all of the oil met the same fate? Why did some of the oil evaporate while some dissolved, and still other bits formed tar balls and washed ashore?
The answer, it seems, is that, according to Oil in the Sea III, a report published by the National Academy of Sciences, oil is a mixture of hundreds of compounds--including benzene, toluene, and heavy metals--the composition of which varies from source to source and over time. The hours-long journey that the oil makes from the well head to the ocean surface causes the oil to fractionate into its component chemicals, leading the heavier compounds to drift to the ocean bottom while the lighter compounds rise to the ocean surface.
Once at the surface, the lighter hydrocarbons, also known as light ends, are more prone to evaporation than are the heavier components. Rough seas, high wind, and high temperatures increase the rate of evaporation and the proportion of oil lost this way. The warm, turmultuous water of the gulf has therefore promoted evaporation of the lighter fractions of the spilled oil.
Some of the “hundreds of compounds” in oil are water soluble and dissolve into the surrounding water, a process that occurs more quickly when the oil is finely dispersed. The more soluble compounds turn out to also be the light aromatic hydrocarbons. Thus, the processes of evaporation and dissolution are lumped into one pie of the chart.
What about the 16% of the oil that has “naturally dispersed”? Like with dissolution and evaporation, the character of the oil and the state of the sea influence how much oil is naturally dispersed. Waves and turbulence at the sea surface can promote natural dispersion, causing an oil slick to break up into droplets which then become mixed into the upper levels of the water column. Dissolution, biodegradation, and sedimentation are more likely when the oil remains suspended in the water as droplets. Again, light, low viscosity oil is most prone to natural dispersion.
So the oil that has dissolved or dispersed (naturally or chemically) is not really gone. It is still in the water, it just can't be seen.
Also, unfortunately, some researchers remain wary that oil that has disappeared from the water's surface will reappear onshore in the future, as happened with the 1979 Ixtoc I oil spill. Larry McKinney, director of the Harte Institute for Gulf of Mexico Studies at Texas A&M, Corpus Christi, told Discovery News that dispersants similar to those used on the BP spill were used to break up the Ixtoc oil, which later washed ashore onto Texas beaches. McKinney is worried that the same thing will happen with this spill. "BP used a lot of dispersant and the oil went someplace," he said.
I am quite curious about the use of chemical dispersants with this spill and the microbes that are doing the degradation, so I am writing a post about it. If you are curious too, check out Petroleum to clean up petroleum? on the Buzz blog.
One last thing:
According to the New York Times, reaction to the report (and its associated chart) has been varied among scientists specializing in the issues it raises. In fact, Samantha Joye, a marine scientist at the University of Georgia told the Times that a lot of the report’s content is “based on modeling and extrapolation and very generous assumptions.” She said that the report would have been “torpedoed into a billion pieces” if it had been put out by an academic scientist.
On the other hand, Edward B. Overton of Louisiana State University said that the report might have underestimated the amount of oil that has effectively left the Gulf. See the Times for a full examination of the debate and the applicability of modeling for predicting the amount of oil that remains.
This article describes a new sugar-based compound in development by researchers at the City College of New York that has the potential to make oil slick cleanup a lot easier in the future. The compound turns the oil to gel, which can be easily skimmed from the water's surface. This is a great alternative to dispersants like the ones BP used because it's nontoxic and shouldn't harm ocean organisms. Check out the video on the same page of that stuff in action--pretty cool!
Estimates of the amount of oil that spilled from the ruined Deepwater Horizon wellhead vary greatly, so it's tough to pin down a total amount. (The short answer is, "a LOT.") But that difficulty hasn't stopped a bunch of different sources from trying...
The official estimate is that some 50 million to 140 million gallons spilled.
Boston.com has a nice gallery of images to help visualize just how much oil has spilled in the Gulf of Mexico. (Unfortunately, the numbers and comparisons only reflect the amount spilled as of June 11, so it's a month out of date. But still fascinating.)
The Alaska Dispatch has a counter that estimates the total amount of oil spilled. (They figure some 92,240,117 gallons, or about 2,196,193 barrels, over 87 days.)
And, last, here's a map of the world's largest oil spills.
The new cap BP has placed on the leaking oil well a mile below the surface of the Gulf of Mexico seems like it might actually be working. That means that for the for the first time in almost three months, oil has stopped flowing from the well.
I'm hesitant to let out a cheer for this, if only because we've already had quite a few gotcha-moments with "solutions" in the response to the oil leak. Right now the pressure from the well is being monitored to determine if the cap should stay tightly sealed onto the well or not—if the pressure stays high, that's good, but if the pressure drops, it could mean that the pipe has ruptured underground, which would be bad. Leaks beneath the sea floor would be much more difficult to manage, because the oil would seep up through the sediment in many places, instead of gushing from one broken pipe.
Anyway, here's hoping that the cap holds, leak free, until relief wells are completed and the leaking well can be shut off entirely. Stay tuned...