BP / Gulf Oil Spill – How Big Is It?

It’s time to revisit this subject. NOAA and BP are still saying the spill rate is 210,000 gallons (5,000 barrels) per day, despite plenty of evidence to the contrary. Many in the media continue to uncritically accept this estimate.

Why is it important to get this number right? This is about more than just liability, or PR. You can bet that our future response capacity is going to be overhauled and retooled based on this spill. If we low-ball the spill amount and rate, we run the risk of designing an inadequate new spill-response system that is doomed to fail the next time something this big occurs.

A couple of thoughts:

1) Are we really being asked to believe that the spill-response capability of one of the world’s biggest oil companies AND the United States Coast Guard has been totally overwhelmed by a spill of just 210,000 gallons per day? That’s a big spill, but not nearly as big as could reasonably be anticipated. Plenty of wells in the Gulf produce more than that under controlled flow-rate conditions; plenty of tankers plying our waters hold millions of gallons of oil.

2) BP claims the siphon they’ve inserted into the end of the damaged riser pipe is diverting 84, 000 gallons (2,000 barrels) of oil per day from the main leak to a tanker at the surface. That is good news indeed. But it’s worth remembering that for nearly a week BP stated the total spill rate was only 1,000 barrels per day.

3) Scientists analyzing video of that main leak, apparently shot on May 11 and released by BP on May 12, have estimated the flow rate from that leak to be anywhere from 20,000 to 100,000 barrels per day. This makes SkyTruth’s 1.1 million gallon (26,500 barrel) per day estimate, based on our measurements of the oil slick as observed on satellite images and mapped by the Coast Guard, look fairly conservative. And it doesn’t even include the additional 15-20% coming from the secondary leak. That means BP’s siphoning effort is only capturing, at best, about 10% of the flow. This video of the main leak, shot on May 17 after the siphon was inserted and apparently working, shows the plume of oil continuing to spew into the Gulf; it hardly looks abated.

4) Speaking of which: video shot on May 15 and 16 has just been released showing the secondary leak, where the riser pipe is kinked and bent about 90 degrees a few feet above the blowout preventer stack. Unlike the short, blurry clip of the main leak, this video is several minutes long and quite sharp.

21 replies
  1. Ian says:

    Pass the envelope. A full throttle fire hose has a diameter of 1.5" and puts out 150 gal/min. If the hole in the bent pipe is 3" in diameter, then it has an area about 4x a fire hose. That makes 600 gal/min or 20,000 bpd. Go ahead, tell me the hole is only 2" in diameter. There are *two* roughly equal jets escaping from the bent riser. They has SO been lying to us about 5000 bpd. Why? We know why BP would lie, but the Coast Guard? 'Sup with that?

  2. Mithras61 says:

    I've reached the point where I believe that the CG/NOAA lie is about more than just covering BP's backside. I believe that they are scared. They think we will panic if the true extent of the gusher is known generally.

    I also think its time to quit trying to save this well and just shut it down. BP is doing their dead-level best to save the well, and plan to worry about the clean-up later. We need to cut this well off and worry about getting to the oil later.

  3. Igor says:

    This number – 2,000barrels/day ( if it is correct) – actually suggests that overall leak may well be above 100,000 barrel/day range. Why? They have inserted 9 inch diameter pipe in 21 inch diameter riser. The flow of oil is split between what is left of the riser (the end of it) and the inserted pipe, which is going all the way to the surface and is about 5000 feet in length… Yes, based on the cross-section ratio such pipe may have 20% of total flow, which is coming currently through the end of the riser. But actual flow depends on hydrodynamic resistance of pipe and pressure applied. Even preliminary estimates show, that the difference in hydrodynamic resistance (and therefore flow output) between the end of truncated riser and one mile long 9’’ pipe will be at least 100-200-fold… Difference in pressure drops for inserted pipe and the riser may be as much as 4-fold, but not more… (60 bar at the ocean bottom – for the riser, and 210 bar – for the pipe). That would not compensate hydrodynamic resistance differences so much as we may hope.
    Of course, if some sort of a sealing is used, that changes the picture, but BP did not mention it, as far as I know…
    In other words – oil will rather flow through wide open hole in the riser at the bottom of ocean, then go through one mile long narrow pipe.
    This suggests, that if BP collects 2,000 barrels/day of oil, then indeed the rate of spill may be more than 100,000 barrels/day.

  4. Draugluin says:


    I'm also worried about NOAA's among some other officials' part in this event. There are so many contradictions: BP got permission to keep shooting dispersants tailored for surface usage despite worries about its ecological impact. NOAA and university researches are having different views both the scale of the leak as well as the course of it: NOAA says it has not entered the Gulf loop, while scientists say it has.

    Is it downplaying vs. fearmongering? It would make sense, because making decisions under panic won't help at all. On the other hand, keeping people guessing will not restore the confidence.

    I believe BP realised the scale of disaster from the day one. BP hoped they can seal the well quick enough and got permission to make it look like rather small one. But the odds were against them and now hopes for easy recovery is long behind and officials need to keep the show of the theatre up. If they just admitted anything at this point citizens would most likely want heads roll – even before the disaster is overcome.

  5. ghon says:

    Your estimates are based on the size of the oil slick and the surface area it covers i believe with an estimate of the surface depth of thickness of the oil. What about these massive plumes or clouds of oil that they are finding now that could be 10 long by 4-5 miles
    wide what would this do to your estimate. Could we now say with these new oil cloud discoveries that even your estimates are probably a good bit low? Also the currents underneath the water to not adhere to the wind so these clouds could of already spread further then we think. This is just one link u can find this story in many places.


  6. Jerry Critter says:

    Your analogy to a fire hose breaks down on several levels. The flow rate from the leak hole(s) not only depends on the cross-sectional area of the hole(s), but also

    1. The rate of flow depends directly on the pressure upstream of the hole. Higher the pressure, greater the flow.

    2. The rate depends on the proportion of the flow that is natural gas, water, and oil. Higher the gas rate, lower the oil rate.

    That being said, there appears to be ample evidence that the 5000 bpd estimate is low, maybe low by more than an order of magnitude.

    Why would the Coast Guard lie? The government failed on their oversight. They are covering their own asses. Plus, the oil industry donates lots and lots of money to politicians. They expect something in return. It is now payback time.

  7. daniel says:

    Thank you sky truth, I guess we can't believe
    one thing we are being told about this,
    I read somewhere that BP and the Coast Guard
    ran some reporters off the beach this morning

  8. John says:

    Thanks all for your comments. We've said all along that SkyTruth's estimates, and those of Dr. MacDonald at FSU, were bare-minimum estimates because they assume that every drop of oil that had leaked from the well had survived, made it to the surface, and was present and accounted for in the surface oil slicks we were measuring. Clearly that is not possible: much of the oil was burned up during the 2-day fire on the doomed rig; some has been driven back into the water column by aerial dispersants and by natural wind-and-wave action; emulsified at the point of the leak by underwater injection of dispersants into the oil plume; collected by the skimmer crews working diligently 24/7; and destroyed by evaporation, biodegradation, and ultraviolet light. So our estimates have been, in our opinion, careful and conservative.

  9. environmentalist says:

    CBS News:

    Republicans for the second time blocked legislation that would increase oil companies' liability for oil spill damages, setting off criticism from Democrats seeking to make BP pay for the disastrous oil spill in the Gulf of Mexico.

    Sen. James Inhofe (R-Okla.) on Tuesday blocked a bill Democrats have put forward to raise the liability cap from $75 million to $10 billion. He said on the Senate floor he agrees the cap should be raised, but the Senate should "wait and see where the cap should be."

    Should there even be a cap? I mean, if you cant afford to clean up the mess you make, should you even be in the business?

  10. Skruffy says:

    I, too, am convinced that the CG and NOAA are pretty much reading scripts written by BP, or at least are going out of their way not to dispute anything BP says. Without going all political… I am retired from a NOAA agency… and you'd better believe that science is censored. NOAA is part of Dept of Commerce… and I was told more than once, literally, that saying things (even if true)that could harm "commerce" goes against the Department's mission statement about "promoting commerce".

  11. Draugluin says:

    For those who wonder why the liability cap is so small we need to remember that it would drive off all small business, because they neither can afford getting in nor can get insurance backup. What I find disturbing in this disaster is total negligence of safety measures and protocols and thus company (or companies) distributing to this devastation should pay every dime of damage they've caused – no matter what the cap is.

    Accidents do happen even with careful action but I guess hardly no one can say that was the case here.

  12. Skruffy says:

    John, hats off to you and others who estimated the volume of the flow days ago much more accurately than BP. Now that BP can measure the amount of oil they are collecting, they're admitting they "underestimated". They weren't just "wrong"… they got caught lying.

  13. richflocker says:

    In a 60 minutes report Sunday, a driller/operator who survived shared that the pressures just prior to the blowout was ~3500 PSI – 7 times the normal range. If the pressure driving this oil and gas is even half that (1750 PSI) and the blowout preventor seal is gone (damaged a week prior, and seal rubber chunks came up in the mud and BP official said to ignore it), then what would the flow rate be out of the pipe at 1700 PSI assuming it's a normal opening area for the BOP?

  14. enigma4ever says:

    Thanks for all of your hard work on this, I am hoping now that the livecam is available for more scientists and engineers to see we can get some better numbers. We really need to know solid numbers before the Hurricane season hits and we also need better reporting and updating by NOAA…

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