Guyana’s offshore oil industry moved 260 crude cargoes in 2025, carrying production from four floating production, storage and offloading (FPSO) vessels operating in the Stabroek Block to international markets.
Every tanker carrying Guyana’s crude must operate within a global framework of maritime rules designed to manage vessel safety, navigation, cargo transfer and environmental protection.
These procedures are outlined in the environmental impact assessments (EIA) for ExxonMobil’s offshore projects, including Liza 1, Liza 2, Payara, Yellowtail, Uaru, Whiptail, Hammerhead and the proposed Longtail development.
According to the Longtail EIA, before cargo transfer begins, export tankers arrive at designated waiting areas several kilometers from the FPSO. The timing of their approach depends on weather and ocean conditions, which can affect offshore operations.
When conditions are suitable, a mooring master boards the tanker approximately two kilometers from the FPSO to assist with the final approach and support the offloading operation.
The mooring master helps coordinate communication between the tanker, FPSO personnel and support vessels, while also assisting with mooring activities that connect the tanker safely to the production facility.
However, responsibility for the vessel remains with the tanker’s vessel master, who is responsible for the ship’s safety, security and compliance with applicable regulations throughout the operation.
Once the tanker is positioned alongside the FPSO, crude transfer operations begin. The process requires close coordination between tanker crews, FPSO operators and support vessels to ensure cargo is transferred safely.
After loading is completed, the tanker undergoes documentation checks and safety procedures before departure.
The rules that guide every voyage
The Longtail EIA explains that movement of crude oil by sea is governed by international conventions and industry standards that establish common safety requirements for vessels operating around the world.
One of the key frameworks is the International Convention for the Safety of Life at Sea (SOLAS), developed by the International Maritime Organization (IMO).
According to IMO, SOLAS 1974 is one of the key international agreements governing ship safety. The convention establishes minimum requirements for the construction, equipment and operation of vessels to ensure they can operate safely at sea. Its requirements cover areas such as navigation safety, emergency preparedness, communications, life-saving equipment and the overall management of ship operations, helping to create consistent safety standards for vessels operating across international waters.
Tanker operations are also guided by the International Convention for the Prevention of Pollution from Ships (a.k.a. MARPOL), another IMO convention.
The framework includes requirements related to oil pollution prevention, tanker design features such as double hulls, ballast systems and operational practices aimed at reducing environmental risks during shipping activities.
For crude oil handling, operators also rely on the International Safety Guide for Oil Tankers and Terminals (ISGOTT). The guide provides recommended procedures for tanker and offshore facility operations, covering areas such as communication, mooring, cargo transfer, emergency preparedness and the responsibilities of both vessels and offshore facilities during loading activities.
The Oil Companies International Marine Forum (OCIMF) also develops industry recommendations and best practices to improve safety during the transportation and handling of crude oil, petroleum products and gas.
The organization works with companies across the global energy industry to support safer tanker operations, including activities such as vessel inspections, cargo handling and offshore transfer operations.
Guyana’s oil production is expected to grow from current levels of around 900,000 barrels per day (b/d) to more than 1.4 million b/d by 2027 as new Stabroek Block developments, including Uaru and Whiptail, come online.
ExxonMobil operates the Stabroek Block with a 45% stake, with co-venturers Hess 30%, and CNOOC 25%. The Stabroek Block’s estimated discovered resource is approximately 11 billion oil-equivalent barrels.
