World’s Biggest New Oil Find Turns Guyana Upside Down

Opponents say the country should be getting more from the Exxon-led consortium amid questions of how the deal was handled

GEORGETOWN, Guyana—To mark the flow of the world’s biggest oil discovery in years, President David Granger declared a new holiday, National Petroleum Day, on Dec. 20.

Backed by soothing Caribbean tunes in a video address to his countrymen, Mr. Granger said oil riches would soon transform this poor South American country, and he would put the proceeds to work for all through a sovereign-wealth fund that prioritized investment in education and infrastructure.