BP oil spill rate in Gulf may be 3 million gallons per day

Image from a video released by BP PLC shows oil spewing from a yellowish, broken pipe 5,000 feet below the surface.

AP Photo/BP PLC

The oil gushing out of BP’s uncontrolled oil well may be at a rate which dwarfs previous estimates, according to an analysis from experts and reported on NPR on Friday. The spill is a result of the explosion and subsequent sinking of the Deepwater Horizon oil rig which occurred on April 20.

If the new flow estimate is correct, over 70.5 million gallons of oil have thus far been released into the waters of the Gulf of Mexico since April 20, to the detriment of the ecology and the economy of the region.

Up to now, the previous estimate based upon oil on the surface stated the amount of the spill at 5,000 barrels, or 210,000 gallons per day. Purdue University Associate Professor of mechanical engineering Steven Wereley, however, has created a program to track the particle flow of material from the open pipe, and has created new estimates of the open flow of approximately 70,000 barrels or 2.9 million gallons a day, within an accuracy of 20%. This deviation creates a range of the spill at anywhere from 56,000 barrels, or 2.4 million gallons a day to 84,000 barrels, or 3.5 million gallons per day.

Wereley, who is an expert in the field of fluid mechanics, has co-written Particle Image Velocimetry: A Practical Guide and Fundamentals and Applications of Microfluidics.

“I spent a couple of hours this afternoon analyzing the video, and the number I get is 70,000 barrels a day coming out of that pipe,” Wereley stated, according to the Los Angeles Times. He continued, “BP has said you can't measure this. I agree you can't measure [the flow] to a very high degree of precision, but that doesn't mean you can't get a good estimate. This estimate, I think, is much better than the 5,000 barrels a day they have previously been floating.”

Wereley’s estimate was based upon a video released by BP on Wednesday, May 12 which shows the flow of one of the two leaks. According to him, though the leak shows methane being released in addition to the oil, the oil by far appears to be the majority of material being ejected.

Steven Wereley’s estimation is not the only new one being calculated. As reported by NPR, there are two other estimates. Scientist Timothy Crone from Lamont-Doherty Earth Observatory estimated a flow of at least 50,000 barrels or 2.1 million gallons per day. In addition, astrophysicist Eugene Chaing calculated a volume of anywhere from 20,000 to 100,000 barrels, or 840,000 to 4.2 million gallons per day.

Previously, the 5,000 barrel (210,000 gallon) a day estimate was questioned by Florida State University professor of oceanography Ian MacDonald who had instead estimated a volume of at least 20,000 barrels per day.