Based on new pressure readings, data, and analysis, the U.S. scientific teams charged by National Incident Commander Thad Allen with determining the flow of oil from BP’s leaking well have refined their estimates of the oil flow prior to the well being capped on July 15.
Today’s estimates, which draw heavily on recent oil reservoir modeling and on pressure readings of a closed system, are the most accurate to date and have an uncertainty of plus or minus approximately 10 percent.
Recent measurements and modeling also show that, as a result of depletion of the hydrocarbon reservoir, the daily flow rate decreased over the 87 days prior to the well’s closure. Based on these measurements and modeling, the scientific teams estimate that, at the beginning of the spill, 62,000 barrels of oil per day were leaking from the well.
Overall, the scientific teams estimate that approximately 4.9 million barrels of oil have been released from the well. Not all of this oil and gas flowed into the ocean; containment activities conducted by BP under U.S. direction captured approximately 800,000 barrels of oil prior to the capping of the well.
Therefore, 4.1 million barrels of oil leaked into the Gulf of Mexico.
This would make it smaller than the Lakeview Gusher of 1910 and 1911 off of California and perhaps smaller than the Gulf War oil spill (where Iraq destroyed Kuwait oil infrastructure before retreating in the first Gulf War)
The BP spill would be about 20% larger than the Ixtoc I Gulf of Mexico spill of 1979-1980.