ExxonMobil sanctions $12.5B Longtail development offshore Guyana

By James Calloway

ExxonMobil has approved an additional $12.5 billion for the Longtail gas and condensate development offshore Guyana and targets a 2030 start. The company said the final investment decision followed approvals from the Guyanese government and regulators.

What did ExxonMobil approve?

The sanction makes Longtail the eighth development in the Stabroek block. It targets non-associated gas and condensate-rich reservoirs in the southeastern part of the block, rather than an oil project tied to existing output.

According to ExxonMobil, the development plan includes:

• A floating production, storage and offloading vessel, or FPSO, designed to process 1.2 billion standard cubic feet of gas per day.
• Up to 250,000 barrels of condensate per day.
• Approximately 45 subsea production and injection wells.

The FPSO capacity gives Longtail a larger gas-processing role than its condensate production target alone suggests. For the project team, the decision moves Longtail from planning into funded execution, with engineering and construction still ahead.

What does the vessel and well program change?

ExxonMobil Guyana hired SBM Offshore in early 2026 to conduct front-end engineering and design studies for the Longtail FPSO. That work covers the vessel that ExxonMobil plans to deploy at the development.

The FEED appointment does not complete the vessel. Fabrication, installation and commissioning remain separate stages before the well program can deliver gas and condensate at the target rate. The FID nevertheless gives contractors, engineering companies and subsea suppliers a defined project around which to organize execution.

For operators and service companies, the practical change is a committed development program rather than another proposed Stabroek project. The next technical milestones will be the FPSO design and the subsea execution plan.

Can Longtail gas reach shore?

ExxonMobil said Longtail gas could eventually travel to shore through a pipeline. The company has tied that option to future investment decisions, market demand and development of the necessary infrastructure.

A pipeline therefore remains outside the sanctioned scope described in the announcement. Three conditions still stand between the offshore development and a shore-gas project:

• A future investment decision.
• Sufficient market demand.
• Development of the required infrastructure.

Until those conditions are met, operators should not treat Longtail gas exports to shore as a committed part of the 2030 development. Gas production is sanctioned; a pipeline route is not.

How does Longtail fit the Stabroek production sequence?

ExxonMobil currently produces about 900,000 barrels of oil per day from four projects in the Stabroek block. The company expects its fifth project, Uaru, to start in the fourth quarter and lift output above 1 million barrels per day.

Construction continues on Whiptail and Hammerhead, the sixth and seventh approved Stabroek developments. ExxonMobil expects Whiptail production to begin in 2027 and Hammerhead production in 2029. Longtail follows with a target start in 2030.

That sequence gives the block a staged expansion rather than a single step change. The nearest production increase depends on Uaru, while Longtail sits at the back of the current development schedule and adds gas-processing capacity beyond the existing oil-led output.

Who owns and supports the block?

ExxonMobil Guyana Limited operates Stabroek with a 45% interest. Hess Guyana Exploration holds 30%, and CNOOC Petroleum Guyana holds 25%. The partners share both the operating position and the capital requirements of future developments.

ExxonMobil reported that ExxonMobil Guyana and its contractors have spent more than $3.9 billion with Guyanese suppliers since 2015. Approximately 6,000 Guyanese workers currently support operations in the block.

Those spending and employment figures cover cumulative Stabroek activity since 2015, not the Longtail project alone. Longtail now adds another capital program to an existing contractor and supplier network in Guyana.

What should operators watch next?

The main watch item is a future investment decision on taking Longtail gas to shore. A market-backed pipeline plan would change the project's commercial scope, but the current announcement does not commit ExxonMobil to that infrastructure.

The technical schedule also matters. SBM Offshore's FEED work must mature into an FPSO execution program, while the roughly 45-well subsea campaign must fit ExxonMobil's targeted 2030 startup.

The decisive next watch item is the pipeline investment decision, while the wider Longtail development remains targeted for production in 2030.