The Trump administration is poised to relax offshore drilling requirements imposed in response to the Deepwater Horizon disaster that killed 11 people in 2010 and unleashed the worst oil spill in U.S. history. The Interior Department will unveil its final plan Thursday to ease some of the mandates, following industry complaints they are unwieldy and expensive, said two people familiar with the matter who asked not to be named before a formal announcement. The White House Office of Management and Budget said it had completed a review of the drafted regulation on Monday, clearing it for a final release.