FILE - In this aerial file photo madeWednesday, April 21, 2010 in the Gulf of Mexico, more than 50 miles southeast of Venice on Louisiana's tip, an oil slick is seen as the Deepwater Horizon oil rig burns. Nearly three years after the deadly rig explosion in the Gulf of Mexico triggered the nation's worst offshore oil spill, a federal judge in New Orleans is set to preside over a high-stakes trial for the raft of litigation spawned by the disaster on Monday Feb. 25, 2013. (AP Photo/Gerald Herbert, file)

FILE - Oil from the Deepwater Horizon spill floats on the water as the sky is reflected in sheen on Barataria Bay, off the coast of Louisiana, in this June, 7, 2010 file photo. A high-stakes trial to assign blame and help figure out exactly how much more BP and other companies should pay for the spill began Monday, Feb. 25, 2013. (AP Photo/Charlie Riedel)

FILE - This file photo provided by the U.S. Coast Guard shows oil leaking from the drill pipe of the Deepwater Horizon drilling rig after it sank on April 22, 2010, two days after it exploded. A high-stakes trial to assign blame and help figure out exactly how much more BP and other companies should pay for the spill began Monday, Feb. 25, 2013. (AP photo/US Coast Guard)

FILE - Oil floats in the waters of Chandeleur Sound, La., in this file photo taken May 4, 2010, two weeks after the explosion of the Deepwater Horizon oil rig in the Gulf of Mexico. A high-stakes trial to assign blame and help figure out exactly how much more BP and other companies should pay for the spill began Monday, Feb. 25, 2013. (AP Photo/Eric Gay, File)

FILE - A sea bird is mired in oil on the beach at East Grand Terre Island along the Louisiana coast in this June 3, 2010 file photo. Oil from the Deepwater Horizon has affected wildlife throughout the Gulf of Mexico. A high-stakes trial to assign blame and help figure out exactly how much more BP and other companies should pay for the spill began Monday, Feb. 25, 2013. (AP Photo/Charlie Riedel, File)

FILE - United States Fish and Wildlife biologist Kayla Dibenedetto attempts to catch an oiled Brown Pelican at Grand Isle, La., in this June 5, 2010 file photo. Oil from the Deepwater Horizon has affected wildlife throughout the Gulf of Mexico. A high-stakes trial to assign blame and help figure out exactly how much more BP and other companies should pay for the spill began Monday, Feb. 25, 2013. (AP Photo/Charlie Riedel, File)

FILE - Crude oil from the Deepwater Horizon oil spill washes ashore in Orange Beach, Ala., in this June 12, 2010 file photo. Large amounts of the oil battered the Alabama coast, leaving deposits of the slick mess some 4-6 inches thick on the beach in some parts. A high-stakes trial to assign blame and help figure out exactly how much more BP and other companies should pay for the spill began Monday, Feb. 25, 2013. (AP Photo/Dave Martin, File)

FILE - A small dead fish floats on a pool of oil at Bay Long, off the coast of Louisiana, in this June 6, 2010 file photo. Oil from the Deepwater Horizon has affected wildlife throughout the Gulf of Mexico. A high-stakes trial to assign blame and help figure out exactly how much more BP and other companies should pay for the spill began Monday, Feb. 25, 2013. (AP Photo/Charlie Riedel, File)

FILE - Greenpeace worker Lindsey Allen collects samples of oil that washed up along the mouth of the Mississippi River near Venice, La., in this file photo taken May 19, 2010, a month after the Deepwater Horizon oil rig explosion in the Gulf of Mexico. A high-stakes trial to assign blame and help figure out exactly how much more BP and other companies should pay for the spill began Monday, Feb. 25, 2013. (AP Photo/Charlie Riedel, File)

FILE - An oil-soaked bird struggles against the oil-slicked side of the HOS Iron Horse supply vessel at the site of the Deepwater Horizon oil spill in the Gulf of Mexico, off the coast of Louisiana, in this May 9, 2010 file photo. A high-stakes trial to assign blame and help figure out exactly how much more BP and other companies should pay for the spill began Monday, Feb. 25, 2013. (AP Photo/Gerald Herbert, File)

FILE - In this May 24, 2010 file satellite image provided by NASA, sunlight reflects off the lingering oil slick from the Deepwater Horizon oil rig explosion off the Mississippi Delta. A high-stakes trial to assign blame and help figure out exactly how much more BP and other companies should pay for the spill began Monday, Feb. 25, 2013. (AP Photo/NASA, File)

FILE - People hold hands during a Hands Across the Sand event in Tybee Island, Ga., in this file photo taken June 26, 2010, about two months after the explosion of the Deepwater Horizon oil rig in the Gulf of Mexico. A high-stakes trial to assign blame and help figure out exactly how much more BP and other companies should pay for the spill began Monday, Feb. 25, 2013. (AP Photo/Stephen Morton, File)

FILE - BP PLC Chief Executive Officer Tony Hayward asks members of the media to step back as he walks along Fourchon Beach in Port Fourchon, La., in this file photo taken May 24, 2010, about a month after the Deepwater Horizon oil rig explosion in the Gulf of Mexico. Hayward visited the beach to observe efforts to clean oil that washed ashore from the spill. A high-stakes trial to assign blame and help figure out exactly how much more BP and other companies should pay for the spill began Monday, Feb. 25, 2013. (AP Photo/Patrick Semansky, File)

FILE - BP senior vice president Kent Wells rubs his eyes while testifying during the Deepwater Horizon joint investigation hearings by the U.S. Coast Guard and the Interior Department's Bureau of Ocean Management, Regulation and Enforcement in Houston in this Aug. 26, 2010 file photo. A high-stakes trial to assign blame and help figure out exactly how much more BP and other companies should pay for the spill began Monday, Feb. 25, 2013. (AP Photo/David J. Phillip, Pool, File)

FILE - A Capitol Hill police officer arrests Diane Wilson on Capitol Hill in Washington as BP CEO Tony Hayward testifies before the Energy and Environment subcommittee on Oversight and Investigations hearing on the role of BP in the Deepwater Horizon Explosion and oil spill in this June 17, 2010 file photo. A high-stakes trial to assign blame and help figure out exactly how much more BP and other companies should pay for the spill began Monday, Feb. 25, 2013. (AP Photo/Haraz N. Ghanbari, File)