** FILE ** In this aerial file photo created on Wednesday, 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)