Years of corruption, underinvestment, fires and thefts have left the nation’s crude infrastructure in tatters. Rebuilding it enough to lift Venezuela’s output back to its peak levels of the 1970s would require companies that could include Chevron Corp., Exxon Mobil Corp. and ConocoPhillips to invest about $10 billion per year over the next decade, said Francisco Monaldi, director of Latin American energy policy at Rice University’s Baker Institute for Public Policy.