The government estimates just came out, they are sticking with the estimate of 12,000 to 19,000 barrels of oil per day leaking from floor of the Gulf of Mexico.
Previous estimates were much higher
The way they came up with this value was by combining two independent teams that used different methods of measurement. One method took info directly from the source and came up with a higher value. Another was full of assumptions and low-ball figures, using surface estimates of the spill.
Then the managers combined both values as though they were just as accurate and came out with the low-ball figure.
US govt pegs BP well flow rate at up to 19,000 bpd
HOUSTON, May 27 (Reuters) - U.S. government experts have estimated that BP Plc's blown-out well in the Gulf of Mexico is spewing up to 19,000 barrels (798,000 gallons) per day of oil, the director of the U.S. Geological Survey said on Thursday.
Up to now, BP has estimated the leak at 5,000 barrels (210,000 gallons) per day, but has said that figure is unreliable. (Reporting by Chris Baltimore)
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Methodology: As reported by CNN, two teams of scientists worked independently to perform their analysis. One used video feeds and advanced particulate image velocimetry to determine how much oil and gas mixture was flowing from the leaks.
previous estimates using this technology determined that the flow rate was
•
Video analysis
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Chang (UCB): 20,000-100,000 bbl/day
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Crone (Columbia): 20,000-100,000 bbl/day
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Wereley (Purdue): 56,000-84,000 bbl/day
Please note that every analysis performed using this advanced technology directed at the source of the leak has a minimum flowrate that is greater than the maximum estimate by the government.
The fact that this estimate is so low is an extremely low probability of being correct.
how did they come up with this then?
well, according to CNN
A second team of scientists used flyover mapping technology and assumed slick volumes to determine the amount of oil on the surface of the ocean. They then made assumptions about how much oil had reached the surface and how much had evaporated to come up with a different value of the daily leak rate.
Then the government panel combined the two processes.
Can you guess which team dragged the estimate lower than the previous estimates?
This is a classic measurement methodology when you want to minimize the results and produce a "safe" or "conservative" measurements.
You find the evaluation methodology that will give you the highest probability of determining exactly what the spill rate is. Then, because you know that you won't like the number, you combine it with a second measurement method that is full of assumptions and will provide a low-ball estimate.
then you combine the two as though they both had equal weight and accuracy.
Voila! 20,000 - 100,000 barrels per day becomes 12,000 - 19,000 barrels per day.
According to Devilstower on the DKOS front page yesterday
Meanwhile, we were supposed to have an "official" estimate from the government over the weekend. Instead we got an official reshuffling of the members of the committee making the estimate. And we still have no number.
So they "reshuffled" the staff that made the estimate only a day before they released their "results" ehhh???
It is crap like this that makes people lose their faith in their government.
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Update: As an afterthought. Remember when the government said they have absolutely no idea how effective the dispersant was because this process had never been done before?
well, this is the great unknown for the second method of analysis. How effective was the dispersant in preventing the oil from reaching the surface? Did 50% of the oil get to the surface? Did 10% of the oil get to the surface?
Until these assumptions are published we just won't know. I expect a full report on my desk in the morning!
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Update 2:
Original estimates of mud flow rate was 65 barrels of mud per minute. This equals a flow rate of 93,600 barrels per day.
since gas and oil did not appear to be leaking during this operation it is safe to assume that the leak rate was lower than this amount.