Tullow Oil, the biggest company on the Irish stock exchange, has now become the biggest explorer in Africa.
It has announced a new project in Uganda, making it the owner of all but one of the landlocked east African nation's oil blocks with proved reserves.
It follows a discovery earlier this week in Ghana, which could be worth around €1bn.
Chief Executive of Tullow Oil Aidan Heavy says all bodes well for the company in Africa.
"It just continues the success we have had in Uganda," Mr Heavey said. "We have drilled 33 wells and made 32 discoveries.
"The proven reserves there now have pushed up to around 950,000,000 barrels so it's a huge area for us."