Culzean, a Leading Offshore Gas Facility in the United Kingdom

Culzean is a gas condensate field located in the North Sea, 230 kilometers off the coast of Aberdeen. It was discovered in 2008 in an area that had been left unexplored for a long time. Its resources are estimated between 250 and 300 million barrels of oil equivalent. The Culzean platform is one of TotalEnergies’ flagship offshore facilities, both in terms of its innovative technological and digital solutions, and the reduction in the greenhouse gas emissions from its activities.

With the acquisition of Maersk Oil in 2018, TotalEnergies became the operator of the Culzean offshore gas field located in Block 22/25a in the East Central Graben area of the central North Sea. This high-pressure, high-temperature (HPHT) gas condensate field is made up of two reservoirs at a depth of 4,300 meters below sea level, with reserves estimated at between 250 million and 300 million barrels of oil equivalent. Production from Culzean started in June 2019 and is capable of meeting 5% of the gas demand in the United Kingdom, where TotalEnergies is one of the main operators in the oil and gas sector.

An unprecedented offshore facility

The depth and size of the reservoirs require a unique approach to production. Culzean has three offshore platforms, linked together with bridges. The first platform is used for drilling and hydrocarbon production, the second for processing and export of produced gas and condensate, and the last for the crew’s living quarters. The project also includes a floating storage and offloading (FSO) vessel measuring 52 meters at its highest point and 243 meters in length. Called the Ailsa, the FSO can store up to 430,000 barrels of oil equivalent of condensate.

We have worked alongside our partners to perfect our technologies at each stage in the Culzean project’s development. More efficient drilling techniques have allowed us to reach depths of up to 5,000 meters. In June 2022, we managed to increase Culzean’s capacity by 10% through improvements in our technologies, reaching production of 550 million cubic meters of gas per day to meet the growing level of demand for gas in the United Kingdom and Europe.

Culzean, TotalEnergies' flagship digital asset in the United Kingdom

Right from the earliest stages of the project, Culzean was equipped with the most sophisticated technologies to ensure safety and performance and facilitate communication and collaboration within the operations teams. For example, the platform includes a SMART (Support and Monitoring of Assets in Real Time) room where data is collected to help manage production and maintenance work. As part of this, the platform’s technicians are provided with handheld devices so they can receive real-time information from the onshore support sites. With its wide array of mobility tools, the platform is also taking steps to digitize maintenance operations and consequently streamline the associated monitoring activities. As such, Culzean has become the standout digital asset in TotalEnergies’ portfolio in the United Kingdom.

Our actions and projects to decarbonize the Culzean platform

In 2024, we announced that the Company was launching a pilot project to install a floating wind turbine to supply renewable electricity to Culzean, thereby paving the way for an innovative decarbonization scheme for our offshore assets. The wind turbine will be located two kilometers west of the platform and 220 km off the coast of Aberdeen. It will be installed on a semi-submersible floater with a light, modular hull designed by Ocergy, a Franco-American start-up specializing in offshore wind solutions. When it comes on stream by end 2025 with a capacity of 3 MW, it will cover approximately 20% of Culzean's needs, in addition to the electricity already generated by gas turbines.

This pilot project will help reduce the platform’s greenhouse gas emissions in line with our objective of reducing Scope 1&2 net emissions from our operated sites by 40% between 2015 and 2030. By saving 3 million standard m³ of fuel gas per year, 6,000 tonnes of CO₂/year will be avoided.

In 2023, a study revealed that two valves in the gas processing sequence required intervention. Making those repairs removed an additional 70 tonnes of CO₂e per day, reducing Culzean’s flaring emissions by 40%.