The company said that the latest discovery adds to the previously announced estimated recoverable resource of approximately 5.5 billion oil-equivalent barrels on the Stabroek Block.

Yellowtail-1 is the fifth discovery in the Turbot area, which ExxonMobil expects to become a major development hub.

ExxonMobil made substantial commercial quantities at the Tilapia-1 and Haimara-1 wells within the Stabroek Block earlier this year.

The Stabroek Block is 6.6 million acres (26,800 square kilometres). ExxonMobil’s affiliate, Esso Exploration and Production Guyana Limited, is the operator and holds 45 per cent interest in the Stabroek Block. Hess Guyana Exploration Ltd holds 30 per cent interest and CNOOC Nexen Petroleum Guyana Limited holds 25 per cent.