Guyana’s Yellowtail crude, from the country’s fourth offshore development, is set to hit international markets in the third quarter of 2025, with a lighter and sweeter profile than the country’s current grades.
The new grade is expected to compete directly with established light-sweet crudes from the United States and Argentina, namely West Texas Intermediate (WTI) and Medanito, S&P said.
S&P Global Commodity Insights reported that, based on a preliminary assay they have reviewed, Yellowtail will have an API gravity of 36.5 and a sulfur content of 0.25%. This marks a difference from Guyana’s existing crude offerings from the ExxonMobil-led consortium developing the Stabroek Block.
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The country’s earlier offshore grades — Liza (32 API, 0.58% sulfur), Unity Gold (34 API, 0.41% sulfur), and Payara Gold (29 API, 0.60% sulfur) — are all medium sweet crudes, S&P said. Yellowtail’s higher API gravity and lower sulfur content place it firmly in the light-sweet category, aligning more closely with global benchmark crudes preferred by refiners for their higher yield of premium products like gasoline and jet fuel.
One source familiar with the assay reportedly told S&P Global that Yellowtail’s API gravity puts it “similar to a lot of Nigerian [crudes],” though its sulfur content remains higher than many West African grades. The source suggested it may trade similarly to Angola’s Nemba.
When compared to U.S. WTI, Yellowtail’s API of 36.5 is slightly lower than the typical WTI range of 39-41. Its sulfur content, however, is competitive, with WTI averaging around 0.24%. Argentina’s Medanito crude, another light sweet grade, has an even lighter API gravity of 40.8 and lower sulfur content at 0.15%. This puts Medanito at the top of the quality scale, but Yellowtail enters the market as a viable competitor.
Yellowtail’s entry will expand Guyana’s export portfolio amid growing production. Stabroek Block’s output currently exceeds 600,000 barrels per day (b/d), supported by three producing projects: Liza Phase One (150,000 b/d), Liza Phase Two (250,000 b/d), and Payara (250,000 b/d). Yellowtail is expected to add another 250,000 b/d, pushing total capacity to 900,000 b/d by year-end.
Production will be handled by the ONE GUYANA floating production, storage and offloading vessel (FPSO), which arrived at the Stabroek Block on April 15. The Yellowtail development could start production in August.
ExxonMobil holds a 45% operating stake in the Stabroek Block, with partners Hess and CNOOC holding 30% and 25%, respectively.
