The Upper Cretaceous play in the Guyana-Suriname Basin is entering a maturing phase following a strong discovery cycle, according to Westwood Global Energy Group’s latest Insights post published June 25.
The analysis shows a broader slowdown in global high-impact exploration activity, with just 64 high-impact wells completed in 2025, a 17% decline from 2024 and the lowest annual total recorded since 2008. These wells delivered 4.8 billion barrels of oil equivalent in discovered resources, with a 31% commercial success rate, slightly above the 28–29% range seen in 2023–2024.
“The scale of the 38 new plays opened in the past 15 years is generally modest with a median play size of ~500mmboe [millions of barrels of oil equivalent]. Only 15 emerging play wells were drilled in 2025, with previously significant plays such as the Upper Cretaceous in Suriname-Guyana now maturing,” Westwood said.
Of the 38 new plays opened since 2011, only eight have exceeded a billion barrels of oil equivalent. More than half of new plays concentrate over 90% of their resources in the initial discovery, limiting follow-up potential.
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“Cretaceous plays have dominated the past five years, accounting for 46% of the primary targets in wells drilled and 65% of the resource discovered (~18.8bnboe). The Lower Cretaceous delivered 68% of the Cretaceous resource (~12.7bnboe), with significantly larger discoveries than other reservoir ages over the five-year period,” Westwood stated.
Key discoveries in 2025 included Bumerangue in Brazil’s Santos Basin, Mopane-3X and Capricornus in Namibia’s Orange Basin, and Hai Su Vang in Vietnam’s Cuu Long Basin. At the same time, exploration failures were recorded in multiple basins, including “Suriname-Guyana, the Niger Delta, Herodotus, Andaman, and Ulleung.”
In 2022, Westwood Energy reported that the Upper Cretaceous play offshore Suriname-Guyana included four discoveries and was dominated by emerging play exploration, adding an estimated 1 billion barrels of oil equivalent.
The Guyana–Suriname Basin continues to be viewed as one of the most prospective deepwater frontiers globally, with analysts frequently drawing comparisons to Brazil’s pre-salt province due to similar geological characteristics and scale potential.
OilNOW reporting has highlighted that continued success in Guyana’s Stabroek Block operated by ExxonMobil and emerging activity offshore Suriname suggest a shared petroleum system that could mirror Brazil’s offshore transformation.
