What rebuilding Venezuela's oil fields will mean for ExxonMobil, Chevron and ConocoPhillips

Regime change could pave the way for the return of U.S. oil companies to Venezuela , which has the largest proven crude oil reserves in the world. President Donald Trump has called for U.S. oil companies to invest billions of dollars in Venezuela’s energy sector, after U.S. forces captured Venezuelan President Nicolás Maduro.