Design specifications for the floating production vessel planned for ExxonMobil’s proposed Longtail project in Guyana allow for higher production, according to the environmental impact assessment (EIA) report submitted by ExxonMobil. This could facilitate increased hydrocarbon production once initial levels are safely achieved.
The executive summary of the EIA report outlines key operating parameters for the Longtail floating production, storage and offloading (FPSO) vessel, including condensate and gas production rates.
Condensate production for the project is expected to average approximately 250,000 barrels per day (b/d), with an upper limit of 290,000 b/d. However, the study states that the FPSO is designed with an upper liquids production limit of about 304,800 b/d, compared with a targeted total liquids production of roughly 254,000 b/d.
The gap between the expected operating rate and the technical upper limit indicates potential to increase output through future optimization once the facility is in stable operation.
For gas production, the project targets around 1.2 billion standard cubic feet per day, while the study lists an upper limit of approximately 1.263 billion cubic feet per day.
ExxonMobil and its co-venturers in the Stabroek Block have previously increased production rates at other offshore developments through debottlenecking and other operational improvements. As with Longtail, previous EIAs also showed that FPSO specifications were designed to safely increase production above nameplate levels.
Such work has added about 130,000 b/d of oil production capacity across the first three projects currently operating in Guyana. Four developments are now producing in the Stabroek Block, and ExxonMobil is expected to explore similar optimization work at the Yellowtail project in 2026.
The Longtail development would be the eighth project proposed in the block and is expected to start production in 2030. A field development plan is expected to follow soon, followed by government review and, by the end of 2026, potential issuance of a production license.
