Exxon Mobil commits $12.5 bn to Longtail offshore Guyana project targeting 2030 start‑up

XOM has made a final investment decision on Longtail, the eighth development in the Stabroek block offshore Guyana, after receiving the required government and regulatory approvals. The company plans an additional $12.5 billion investment in the project, which is expected to come online in 2030.

Longtail marks a new phase for the block: it targets non-associated gas and condensate-rich reservoirs rather than the oil that the earlier developments produce. Its floating production, storage and offloading vessel is designed to process 1.2 billion standard cubic feet of gas per day and produce up to 250,000 barrels of condensate per day, fed by approximately 45 subsea production and injection wells. Exxon said gas from Longtail could be piped to shore, subject to future investment decisions, market demand and the development of the necessary infrastructure.

The decision extends a development queue that is already lifting output. Exxon produces approximately 900,000 barrels of oil per day from four Stabroek projects, and it expects production to exceed 1 million barrels per day once the fifth project, Uaru, starts up in the fourth quarter. Whiptail is due in 2027 and Hammerhead in 2029. ExxonMobil Guyana operates the block with a 45% interest, alongside Hess Guyana Exploration at 30% and CNOOC Petroleum Guyana at 25%. Hess has been part of CVX since Chevron completed its $53 billion acquisition in July 2025, so Chevron is Exxon's largest partner in the block, per World Oil.

The near-term milestone to watch is Uaru's fourth-quarter start-up, which would take Stabroek past the 1 million barrel-per-day mark. Further out, the open question for Longtail is the gas-to-shore pipeline, which still depends on future investment decisions and market demand, and on whether the 2030 start-up date holds.