MIAMI, Jan 3 - Venezuela is unlikely to see any meaningful boost to crude output for years even if U.S. oil majors do invest the billions of dollars in the country that President Donald Trump promised just hours following Nicolás Maduro's capture by U.S. forces.

The South American country may have the world's largest estimated oil reserves, but output has plummeted over the past decades amid mismanagement and a lack of investment from foreign firms after Venezuela nationalized oil operations in the 2000s that included the assets of Exxon Mobil and ConocoPhillips.