Nor is the exact size of the spill known with any certainty. Scientists have said that calculating the size of the spill carefully will be critical in order to predict the amount of damage the oil and chemicals could do in the ocean and onshore in the near term and in the future.So what is the flow rate? Is it 5,000 barrels a day, as BP and the government have repeatedly claimed in recent weeks? Or is it closer to 80,000 or 100,000 barrels a day, as some independent analysts have guessed based on footage of the oil gushing out of the riser pipe?
http://www.energyboom.com/policy/flow-rate-remains-critical-unanswered-question-bp-oil-disaster
In addition, no one knows how long it will continue - even the slant hit is not a sure bet (which is why they're drilling two, it could take four or more tries, months away).
This is a huge field under a mile of water with no sure end in sight. No one can say today "This spill is X barrels."
True. But I can guarantee you that BP and the Coast Guard have got the best estimates, and have since not long after the "pump and capture" process has been put in place.
Here is how they know:
1) the size of all the leak points is known (by this point they have 3D CAD models of the whole riser pipe and all the penetrations).
2) the size of the inlet pipe for "pump and capture" is known (obviously, since BP installed it).
3) BP knows how fast they have to run the suction pump so as to draw in the maximum amount of oil and minimum amount of water from that inlet line. Given these facts, "I" could calculate a pretty reasonable figure for the amount of oil flow, and I'm sure that the oil professionals could calculate it even more closely.
Is this an accurate method. No, it's an estimate, since BP has NOT known what the spill flow was prior to the installation of the pump and capture. But it will certainly give the full size of the spill to within a factor of two, and probably closer than that.