Italian oil and gas company Eni has upgraded the resource base of the Ndungu field, offshore Angola, following the successful drilling of another appraisal well.

Situated approximately 10km from the Ngoma FPSO, in the West Hub of block 15/06, the Ndungu field was initially expected to contain between 250 million and 300 million barrels of oil equivalent. The assessment was based on the results of the Ndungu 1 appraisal well.

The estimate was more than doubled from 800 million to 1000 million barrels of oil equivalent, based on preliminary data after drilling the Ndungu 2 appraisal well.

The Ndungu 2 appraisal well is located approximately 5km from Ndungu 1. It encountered 40m of net oil pay (35°API) in the Lower Oligocene reservoirs, with good petrophysical properties.

According to a company statement, the revised estimate makes Ndungu, along with Agogo, the largest accumulation discovered in block 15/06 since it was awarded.

“The systematic and continuous Infrastructure-Led Exploration (ILX) effort conducted by Eni and its partners during the last three years, with the full support of ANPG and Angolan Authorities, leveraged leading edge technology, and allowed to unlock significant additional potential in the complex structural and stratigraphic traps inside block 15/06,” the statement added.

Eni Angola operates block 15/06 with a 36.84% share. Sonangol Pesquisa e Produção (36.84%), and SSI Fifteen Limited (26.32%) are the other stakeholders.

The early production phase of Ndungu has already commenced and a second producer well is expected to come online in the fourth quarter of this year.

Earlier this month, Eni and Algeria’s Sonatrach made a significant oil and gas discovery in the Zemlet el Arbi concession.