May 31, 2022

Can Jaca turn Sao Tome and Principe into new oil producer within the Gulf of Guinea?

Sao Tome and Principe has a chance to become a new oil producer in case of positive results of the recently spudded Jaca-1 new-field wildcat, targeting a Cretaceous-aged basin floor fan. The prospect is located within the offshore Block 06 operated by Portugal's Galp Energia with Royal Dutch Shell as a technical operator. Jaca-1 is the first-ever offshore well to be drilled in Sao Tome and Principe exclusive economic zone (EEZ) and also the first exploration well in distal Gabon-Douala Deep Sea Basin. If successful, the well will prove a working petroleum system in the deep offshore area outboard of the Douala, Rio Muni, and Gabon Coastal basins.

The well is currently being drilled by the Maersk Voyager drillship at a water depth of around 2,500 m, targeting a probe at a total depth of about 4,500 m. If successful, the possible development of the field would involve a floating production, storage and offloading (FPSO) vessel with offshore loading onto shuttle tankers to export the crude oil to market. With prevailing and forecasted oil price expected to remain over $90/bbl until the end of 2023, at $95/bbl the minimum economic field size (MEFS) is estimated to be in the region of 100 MMbbls recoverable, while a discovery of 300 MMbbls is expected to have a NPV of over USD 2.5 billion. At a more conservative Brent oil price scenario of $65/bbl Galp Energia is likely targeting at least 280 MMbbls recoverable, while a discovery of 500 MMbbl will have a value in the region of half a billion USD, with IRR of 10%, a government take less than 40% and a break-even price around $60/bbl. It is worth highlighting that the light oil nature of the crude leads to a quality related price adjustment equal to almost $4/bbl.

Should Jaca-1 be a success, it has the potential to de-risk prospective resources in the Gabon-Douala Deep Sea Basin and play a key role for the future exploration activities within Sao Tome and Principe.

jaca prospect evaluation

Figure 1: Jaca prospect valuation


For more information regarding well, field & basin summaries, please refer to EDIN.(opens in a new tab)
For more information regarding asset evaluation, portfolio view, and production forecasts, please refer to Vantage.(opens in a new tab)

For more information regarding our country activity report, please refer to GEPS(opens in a new tab).
For more information regarding E&P costs please refer to IHS Markit Que$tor.(opens in a new tab)

Posted 31 May 2022 by Erik Meyer, Senior Technical Research Analyst, S&P Global Commodity Insights and

Maria Lupachik, Sr Technical Research Analyst, Upstream Energy, S&P Global Commodity Insights



This article was published by S&P Global Commodity Insights and not by S&P Global Ratings, which is a separately managed division of S&P Global.