An oil and gas field offshore Guyana owned by Tullow, Total and Eco Atlantic contains around 3.9 billion barrels of oil equivalent, an upgrade of around a third to a September estimate, Eco said on Monday.
The Orinduik Block neighbors an Exxon Mobil field which, at an estimated 4 billion barrels of oil equivalent, made Guyana one of the world's most closely watched oil basins.
Tullow owns 60 percent, Total 25 percent and Eco Atlantic Oil and Gas 15 percent in Orinduik.
(Reporting by Shadia Nasralla, editing Louise Heavens)
