Monday, August 02, 2010
U.S. Puts Oil Spill Total at Nearly 5 Million Barrels - NYTimes.com
NEW ORLEANS — Nearly five million barrels of oil have gushed from the BP’s well since the Deepwater Horizon spill began on April 20, federal scientists said on Monday in announcing the most precise estimates yet of the well’s flow rate. The estimates would make this spill far bigger than the 3.3 million barrels spilled by the Mexican rig Ixtoc I in 1979, previously believed to be the world’s largest accidental release of oil.
Federal science and engineering teams estimated that 53,000 barrels of oil per day were pouring from the well just before BP was able to cap it on July 15. They also estimated that the daily flow rate had lessened over time, starting at around 62,000 barrels a day and decreasing as the reservoir of hydrocarbons feeding the gusher was gradually depleted.
The teams believe that the estimates are accurate to within 10 percent. They also reported that of the roughly 4.9 million barrels that had been released from the well, about 800,000 had been captured by BP’s previous containment efforts. That leaves over four million barrels that gushed into the Gulf of Mexico between April 20 and July 15.
The amount of oil estimated to be pouring from the well has been a matter of dispute from the earliest days of the BP spill. Federal and BP officials initially announced that no oil appeared to be leaking, then 1,000 barrels a day, then 5,000 a day, frequently repeating that spill estimates are rough at best and that the main goal was to stop the well. But criticism mounted that no effort was being made to measure the leak with more certainty.
The Obama administration announced the creation of a scientific group dedicated to analyzing the flow rate, which came up with a new estimate of 12,000 to 19,000 barrels a day in late May, a figure that was almost immediately met with skepticism. That, too, was later revised upwards several times before Monday’s announcement. Previous estimates came from analysis of videos from remote controlled vehicles at the wellhead, modeling of the reservoir and measurements of the oil that was collected by surface ships in the response effort.