Wereley joined a team of U.S. engineers and scientists that released a U.S. Department of Interior report on Thursday (June 10), showing that 25,000-30,000 barrels of oil per day are likely leaking from the BP well. That’s significantly higher than the team's May 27 estimate of 12,000-19,000 barrels a day.
The daily flow rates translate into a total of 1.3 million to 1.5 million barrels of oil that have leaked into the Gulf since the Deepwater Horizon explosion on April 20 that killed 11 workers. Now considered the worst in U.S. history, the BP oil spill off the coast of Louisiana is roughly five to six times the size of the Exxon Valdez spill of March 1989. That spill is estimated to have dumped 250,000 barrels of oil, or 10.8 million gallons, into Prince William Sound in Alaska.
Initial estimates by BP and the federal government indicated that 5,000 barrels a day had flowed from the BP well into the Gulf.
The latest oil flow figures are based on data gathered by the federal interagency team, the Flow Rate Technical Group, before BP cut a pipe - called a riser - on June 3.
Wereley and his colleagues plan to issue a third report from the period after the riser was cut and before a containment dome was placed over the damaged well 5,000 feet below the surface on June 4. Since then, BP has been funneling some oil and gas to a drill ship stationed above the spill.
The Flow Rate Technical Group team that included Wereley took video of the plume of oil escaping from the pipe and fed it through computer models. The new result from the Plume Modeling Team ranged from 20,000-40,000 barrels per day, with the most likely value in the 25,000-30,000 barrels per day range. That is up from 12,000-25,000 barrels in the initial analysis.
Wereley's role in the current disaster began May 12 when BP released an initial 30-second video clip of oil gushing from the 21.5-inch pipe. The Purdue professor used a technique called particle image velocimetry (PIV) to create freeze-frame shots from the video. From there, he ran a computer analysis to estimate how far in terms of pixels that the identifiable clumps of oil moved.
Wereley, who has co-written a textbook on particle image velocimetry, then created a conversion from pixels to inches based on the pipe's size to compute how fast oil was flowing from the pipe. Using the area of the pipe and the speed of the oil, he concluded that 56,000-84,000 barrels of oil and gas, had been leaking daily into the Gulf during that five-week period.
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