MEO Australia, the only Australian company with a footprint in Cuba, said ongoing work is expected to translate to more potential oil reserves in the country.

In an update on operations through the end of September, the company, one of the few Western companies working in Cuba, said it identified oil plays in so-called Block 9 that combine for an estimated 8.2 billion barrels of oil in place. The company's best estimate is that it could recover about 395 million of those barrels.

"An assessment of the other two shallower oil play types is ongoing and is expected to add significantly to the potential oil-in-place and resource base of Block 9," the company said in its assessment.

In mid-September, the company said it was selling off parts of its holdings in a potentially lucrative basin off the coast of Australia to help fund opportunities in Cuba, its highest priority asset.

According to MEO, Cuba produces about 80,000 barrels of oil per day. Canada's Sherritt International, the only foreign company producing in Cuba, estimates operating costs of around $9 per barrel.

The Cuban government in 2014 enacted legislation offering corporate tax credits to encourage foreign investments. The U.S. government the same year started easing a 54-year trade embargo on Cuba and later reopened its embassy in Havana.

This month, U.S. President Barack Obama issued an executive directive that could open Cuba to a role in institutions like the International Monetary Fund and the World Bank, which Washington said could provide an advantage to the Cuban economy. On Wednesday, the United States for the first time abstained from voting on a U.N. resolution critical of a Cuban embargo.

MEO said easing U.S. restrictions on Cuba were "clearly a positive step" for the company.