Offshore oil field
Block 15/06 offshore Angola
Up to one billion barrels of oil equivalent
The Ndungu early production (EP) development project commenced oil production in February 2022. It is located in block 1/06, offshore Angola.
Eni Angola operates block 15/06 with a 36.84% stake while the remaining interests in the block are owned by Sonangol Pesquisa e Produção (36.84%), and SSI Fifteen (26.32%).
The project is expected to produce approximately 20,000 barrels of oil per day (bopd).
The commissioning of the Ndungu EP is the third production start-up by Eni Angola in block 15/06 in seven months. The other two fields that commenced production during the period include the Cuica EP, and the Cabaca North development projects.
Ndungu discovery and background
Eni announced the discovery of light oil in the Ndungu prospect, in Angola’s deep offshore block 15/06, in May 2019.
The Ndungu-1 new field wildcat (NFW) well was drilled by the Poseidon drillship in 1,076m-deep waters, a few kilometres away from Eni’s West Hub facilities.
Drilled to a total depth of 4,050m, the discovery well encountered a single 65m oil column, with a net pay of approximately 45m of high-quality oil (35° API), in Oligocene sandstones.
Drilled 5km away from Ndungu-1, the Ndungu-2 appraisal well hit 40m of net oil pay (35° API) in the Lower Oligocene reservoirs.
The Ndungu field is estimated to contain resources of between 800 million barrels of oil equivalent (boe) and one billion boe in place, according to the results of the Ndungu-2 well, announced on 28 March 2022. The field was originally estimated to contain 250 million barrels of light oil in place, at the time of discovery.
A second producer well is expected to come on stream in the fourth quarter (4Q) of 2022.
Ndungu was the fourth commercial discovery in block 15/06, after Kalimba, Afoxe, and Agogo. The four discoveries have a combined resource estimate of 1.4 billion barrels of light oil in place.
Block 15/06 details
Eni signed the production sharing agreement (PSA) for block 15/06 in November 2006, following an international bid.
The first commercial oil discovery through the Sangos-1 well was announced in April 2008 while the second discovery was made in August the same year, by drilling the N’Goma-1 well. The third commercial discovery was made in September 2009 by drilling the Cabaça-North well, at a water depth of 500m, in the north-east part of the block.
The block was estimated to contain more than three billion barrels of oil in place, and 850 million barrels of reserves, based on the results of the successful exploration campaign.
It was developed in two phases, namely the West Hub and the East Hub. The West Hub produced its first oil in November 2014 while the East Hub development commenced production through the Armada Olombendo floating production storage and offloading (FPSO) vessel, in February 2017.
The most recent light oil discovery within the block was made in April 2021 on the Cuica exploration prospect, via the Cuica-1 NFW. The new discovery is estimated to hold 200 to 250 million barrels of oil in place.
The Cuica-1 NFW was drilled as a deviated well by the Libongos drillship, at a water depth of 500m. It reached a vertical depth of 4,100m, and proved an 80m column of 38°API light oil in Mioscene era sandstones. The discovery has the potential to produce approximately 10,000bopd.
Ngoma FPSO details
The FPSO Ngoma is owned by Sonasing and operated by OPS, a 50:50 joint venture (JV) between SBM Offshore and Sonangol.
It was on hire by ExxonMobil under the name of FPSO Xikomba in block 15, offshore Angola. Xikomba was operational for eight years until it was disconnected in 2011.
The FPSO vessel was refurbished and is currently under a 12-year lease with Eni Angola.
Ngoma can process 100,000bpd of oil. It has a gas handling capacity of 115 million metric standard cubic feet per day (Mmscf/d), and a water injection capacity of 120,000bpd.