ExxonMobil said today it made a new oil discovery offshore Guyana at the Yellowtail-1 well, marking the 13th discovery on the Stabroek Block. The 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.