Once home to 3,000 sugar workers, the abandoned Houston sugar estate has gradually been absorbed into the suburban sprawl of Georgetown. About 100 families still live in the uniform one-story cottages built by the state sugar company for workers in the 1960s. For them, the recent changes have brought opportunity.

Like most of Houston’s residents, Ms. Harisha’s ancestors came to Guyana as indentured laborers from India in the late 19th century to replace enslaved Africans on the sugar plantations after the British, who then ruled Guyana as a colony, abolished the slave trade.

When the Indian laborers’ contracts expired, some stayed, becoming Guyana’s largest ethnic group and helping shape a unique, vibrant culture, which looks outward to the Caribbean rather than to its Latin American neighbors.

While the effects of the giant oil discoveries off Guyana’s coast are most obvious in and around Georgetown, they are now beginning to extend a little farther beyond the capital, too.

In a brick shack on the edge of the jungle 15 miles away from Houston, Jason Bobb-Semple, 25, is making his own big bet on oil.

With a $3,000 government loan, he built a small poultry farm and bought 4,000 chicks to meet what he expects to be a booming food demand in a rapidly developing country.