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BP capped its Macondo well three years ago yesterday (July 15th), after it gushed crude oil into the Gulf of Mexico for more than 80 days. It was permanently sealed several weeks later. There's been no reported evidence of further leakage from the well. The wreckage of Transocean's Deepwater Horizon drlling rig remains upside down on the ocean floor nearby.  Researchers have concluded that oil trapped in the wreckage is the likely source of oil sheens that have recently been spotted in the Gulf. The Woods Hole Oceanographic Institution and the University of California at Santa Barbara have published recent studies indicating the oil is not seeping from the sealed-off Macondo well. The researchers analyzed 14 samples collected from the surface of the water during two trips to the Gulf.

BP stated last year, it had capped an abandoned piece of equipment that was believed to be the source of a sheen.