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Methane-Trapping Ice May Have Triggered Gulf Spill

sciencehabit writes with an excerpt from Science that begins: "Methane-trapping ice of the kind that has frustrated the first attempt to contain oil gushing offshore of Louisiana may have been a root cause of the blowout that started the spill in the first place, according to [UC Berkeley] professor Robert Bea, who has extensive access to BP p.l.c. documents on the incident. If methane hydrates are eventually implicated, the US oil and gas industry would have to tread even more lightly as it pushes farther and farther offshore in search of energy."

19 of 341 comments (clear)

  1. Re:Farther offshore? by maxume · · Score: 5, Informative

    Depth, pressure.

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  2. Re:Farther offshore? by T+Murphy · · Score: 5, Funny

    Sharks, which tend to stay relatively close to shore, eat the hydrates to power their lasers. This has caused the hydrates to be in relatively low concentration in shallower areas.

  3. Re:Arctic? by Trepidity · · Score: 5, Informative

    This doesn't really answer why it's not a problem in Alaska, but the temperatures aren't actually much different. Alaskan offshore drilling is in relatively shallow water, which at those latitudes is somewhere in the low single digits C once you get below the ice pack; while this operation in the Gulf was at about 1700 meters depth, where the temperatures are also in the low single digits C. (There's lots of complicating factors, but this graph of depth v. temperature for three different latitudes gives an idea.) There's differences in pressure, which might matter, but also big differences in geology.

  4. Re:Farther offshore? by TubeSteak · · Score: 5, Informative

    Is there a correlation between the amount of methane hydrates and the distance from shore?

    The correlation is between distance from shore and depth + temperature.
    Here's some nice graphs showing depth vs temperature for methane hydrates

    And here's a picture of seafloor depths for context

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  5. Re:probably a bit ignorant here by Anonymous Coward · · Score: 5, Insightful

    Uh, dude, look around you. 99.99% of everything you eat, own, use, buy, throw away or want is brought to you by oil. *Nothing* matches it for chemical versatility, nothing else even comes close to the energy density of oil.

    It's one of our very few true energy sources. There is also hydro-electricity, nuclear electricity, and coal/gas electricity. Everything else is farts.

    You can't run our civilization on electricity alone. All air traffic would immediately and forever stop. Car traffic would essentially disappear. You'll go back to wooden sail ships (how are you gonna mine, refine and transform metal without oil? With coal? Good luck with that, *no one* is gonna want that in their backyard, except poor countries...)

    Food production depends on oil for everything. Fertilizers, harvesting, transportation, transformation and your drive to the supermarket. All oil.

    Your job, your house in the suburbs, your car? Oil.

    You want to know what your kids should learn?

    How to raise, breed and ride horses.

  6. Better Article by bill_mcgonigle · · Score: 5, Informative

    This one has more detail, and is actually really-well written. Really, an AP story with some investigative journalism. Kudos, guy, you're making your co-workers look bad. :)

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  7. Re:Arctic? by LehiNephi · · Score: 5, Interesting

    Hydrates require both high pressure and low temperature to form, along with the proper composition of water and methane. Take away any of the three, and hydrates disappear. Typically the gas/water/oil is warm enough when it reaches the surface that hydrates do not form, and by the time it cools down enough, it has already been processed so that the water and methane are no longer mixed.

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  8. Re:probably a bit ignorant here by Trepidity · · Score: 5, Informative

    Oil is really valuable, so there's a very high bar for the monetary cost of disaster to be not worth it, on a purely profits-vs-cleanup-costs basis.

    Some back-of-the-envelope estimates. Say this disaster ends up costing BP $10 billion. Say that any given rig has a 1% chance of causing a disaster of that magnitude. So we assign a $100 million amortized cost per rig, to cover the "chance this rig will catastrophically blow up". Is it still worth drilling in that case? Well, it actually barely changes the economics at all: these deep-water wells cost about $500-600 million to drill and put into production to begin with. So add to $100m to that and total costs are basically still on the same order of magnitude.

    In particular, these rigs can produce a lot of oil. BP's Thunder Horse rig in the gulf produces 250,000 barrels per day. Even if they make only $10/barrel operating profit (probably a low estimate), that's $2.5m per day in profits from the well, i.e. almost a billion dollars per year. Unless fully 10% of such wells incur $10b catastrophic cleanup costs every year, BP comes out ahead.

  9. Re:probably a bit ignorant here by je+ne+sais+quoi · · Score: 5, Informative

    "Wacko environmentalists" have absolutely nothing to do with it. The big problem with doing that is, unfortunately, there's precious little oil left close to shore. You could fill the entire U.S. coast so full of wells it looks like a pin cushion and it would hardly make a dent in the oil price. You can see the chart right here, U.S. oil production has been on a steady decline for decades and will never, ever recover, it doesn't matter how many wells you drill. Even the discovery of the north slope of Alaska and building the pipeline never got the U.S. production to recover from its 1972 peak. ANWR? Forget about it, ANWR's a blip that's laughably too little, too late. This is why the Republican chant of "drill baby drill" is so ridiculous, drilling is pointless without oil to find. We've used up most of the oil near shore, which is why BP was drilling in 5000 feet of water, it has nothing to do with environmentalists.

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  10. Re:Spill baby spill! by interkin3tic · · Score: 5, Insightful

    this is why I'm against sudden rapid expansions of industry into sensitive environmental areas.

    Article says "Drillers have long been wary of methane hydrates because they can pack a powerful punch. One liter of water ice that has trapped individual methane molecules in the "cages" of its crystal structure can release 168 liters of methane gas when the ice decomposes."

    Doesn't exactly sound like this was a new and unforseen problem, it doesn't sound like this happened because we were being hasty. It sounds like it happened because they were on some level being stupid and ignoring a well-known risk. In my book, that's an even stronger reason not to drill. We've known about that for a long time and the oil companies -still- haven't made sure this can't happen? These are not people who should be making potentially environment-altering decisions for the rest of us.

  11. Re:Spill baby spill! by Shakrai · · Score: 5, Interesting

    One liter of water ice that has trapped individual methane molecules in the "cages" of its crystal structure can release 168 liters of methane gas when the ice decomposes."

    I wonder if that can be harnessed as an energy source?

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  12. Re:Spill baby spill! by jbengt · · Score: 5, Informative

    Article says "Drillers have long been wary of methane hydrates because they can pack a powerful punch.. . . " . . . Doesn't exactly sound like this was a new and unforseen problem, . . .

    The drilling is taking place in deeper and deeper water. Deep waters have high pressure and the low temperature. Both of these make formation of methane clathrates more likely. The high pressures a mile beneath the ocean surface also make it easier to dissolve gas in the oil. Avoiding pipeline blockages and explosive decompressions is not trivial. To the extent the industry is pushing the limits of what has been done before (and they are pushing limits of depth) they can be surprised by details that they haven't encountered before.

  13. compensation for vicrims by falconwolf · · Score: 5, Informative

    The good news is that there will be a charity concert in New Orleans, so BP won't have to pay so much money to their victims.

    If it ends up like Vladez oil spill BP won't have to pay anything. More than 20 years later the fish have not recovered and the fishermen have not been compensated. Heck, oil still persists, is still found. Large corporations laugh while going to the bank to make another deposit while the people pay.

    Falcon

    1. Re:compensation for vicrims by mi · · Score: 5, Insightful

      If it ends up like Vladez oil spill BP won't have to pay anything.

      The compensatory damages, that Exxon is on the hook for, exceed half a billion dollars. That's in addition to their spending on the actual clean-up...

      The Supreme Court (in a 5-to-3 vote, with your beloved David Souter writing for the majority) did remove the punitive $2.5 billion as "excessive"... But the compensatory $507 million were left standing... Yes, it took much too long. Maybe, if the plaintiffs weren't greedy (greed is only good, when you are making something, that other people want), they would've gotten their compensation 20 years earlier...

      while the people pay.

      "The people" (including The Children[TM]) also use the oil. Every day... We can't do anything without it.

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  14. Re:Alternative sources could compete by oldspewey · · Score: 5, Insightful

    To badly paraphrase Noam Chomsky, capitalists are actually big fans of socialism. They love the idea of socializing harm ... it's the profits they don't like sharing.

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  15. Re:Arctic? by Nebvin · · Score: 5, Informative

    I wonder how they've avoided the problems up around Alaska or other places where it's actually cold enough for there to be ice - much less methane trapping ice.

    I'm a gas field operator in Alberta, and hydrates can be a massive problem, especially when the wells are not big enough to justify dehydrating the gas at the well site and has to flow to a central facility. Since I operate a sour gas field (contains hydrogen sulfide) the problem is even worse. At our normal field pressures the gas starts to hydrate at around 20 C (68 F) if we are not taking extra steps to control it. It is one of the biggest causes of equipment damage and injuries/deaths. I have never operated oil wells so I am not knowledgeable about how they effect production of oil, but I have read about deaths due to mishandling hydrates at the wellhead of oil wells in Alberta and BC. To reduce the rate that they form, we inject chemicals such as methanol into the gas, and have line heaters at regular intervals along the pipeline. They are a regular problem and danger.

  16. ExxonMobile doing great by jeffsenter · · Score: 5, Insightful

    Sadly, BP should hope that things work out for it the way things worked out for ExxonMobile after the catastrophe of the Exxon Valdez.

    Exxon had a drunk for a captain who crashed a poorly designed oil tanker causing one of the worst environmental disasters in history. The region's environment still has not recovered two decades later. But ExxonMobile sure has! ExxonMobile is the most profitable company in the world. From 2005-2009 the annual profit for ExxonMobile averaged $36 Billion!

    The US Supreme Court was also generous enough a few years ago to reduce the punitive damages award against ExxonMobile for the Valdez from an original jury amount of $5 Billion down to $500 Million (about five days worth of profits).

  17. Re:Spill baby spill! by danlip · · Score: 5, Insightful

    The problem is that #4 is ofter #1 in disguise, i.e. nothing much happens to make the transition. And no one is really advocating #2 or #3, they're just used as the bogeyman by the people trying to stop the real #4.

  18. Re:Spill baby spill! by budgenator · · Score: 5, Interesting

    "This well had been giving some problems all the way down and was a big discovery. Big pressure, *16ppg+ mud weight*. They ran a long string of 7" production casing - not a liner, the confusion arising from the fact that all casing strings on a floating rig are run on drill pipe and hung off on the wellhead on the sea floor, like a "liner". They cemented this casing with lightweight cement containing nitrogen because they were having lost circulation in between the well kicking all the way down. The calculations and the execution of this kind of a cement job are complex, in order that you neither let the well flow from too little hydrostatic pressure nor break it down and lose the fluid and cement from too much hydrostatic. But you gotta believe BP had 8 or 10 of their best double and triple checking everything. On the outside of the top joint of casing is a seal assembly - "packoff" - that sets inside the subsea wellhead and seals. This was set and tested to 10,000 psi, OK. This was the end of the well until testing was to begin at a later time, so a temporary "bridge plug" was run in on drill pipe to set somewhere near the top of the well below 5,000 ft. This is the second barrier, you always have to have 2, and the casing was the first one. It is not know if this was actually set or not. At the same time they took the 16+ ppg mud out of the riser and replaced it with sea water so that they could pull the riser, lay it down, and move off. When they did this, they of course took away hydrostatic on the well. But this was OK, normal, since the well was plugged both on the inside with the casing and on the outside with the tested packoff. But something turned loose all of a
    sudden, and the conventional wisdom would be the packoff on the outside of the casing. Gas and oil rushed up the riser; there was little wind, and a gas cloud got all over the rig. When the main inductions of the engines got a whiff, they ran away and exploded. Blew them right off the rig. This set everything on fire. A similar explosion in the mud pit / mud pump room blew the mud pumps overboard. Another in the mud sack storage room, sited most unfortunately right next to the living quarters, took out all the interior walls where everyone was hanging out having - I am not making this up - a party to celebrate 7 years of accident free work on this rig. 7 BP bigwigs were there visiting from town. In this sense they were lucky that the only ones lost were the 9 rig crew on the rig floor and 2 mud engineers down on the pits." TRANSOCEAN DEEPWATER HORIZON EXPLOSION-A DISCUSSION OF WHAT ACTUALLY HAPPENED? Reply by Garry Denke on May 4, 2010 at 6:06pm

    The "kicks" he's talking about are pressure surges from gas in the well, so everybody knew what the well was doing because it was kicking all the way down, so no surprises there. The well was drilled, Halliburton was contracted to cement the casing which was done and tested and they were pumping out the mud from the riser pipe and filling it with seawater when the explosion occurred. The riser pipes is rated for 15,000 PSI and have a 3.5 million pound load-carrying capacity, between these riser pipes and the blowout preventer is a connector device rated for 7 million foot-pounds of bending load capacity. Right now this riser pipe comes out of the well head goes up 1500 feet and is bent over and the free end is now buried in the seabed. I don't see where they were cutting costs too much. Deepwater Horizon would probably have disconnected from the well and moved on in a day or two if there hadn't been an explosion.

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