Culzean

Culzean Gas Condensate Field Profile

The Culzean gas condensate field is located in the UK sector of the Central North Sea, approximately 230 kilometers (145 miles) east of Aberdeen, in Block 22/25a (License P111) of the East Central Graben area.
The field is situated in a water depth of about 88 meters, with the reservoirs located at a depth of around 4,300 meters below sea level.

The Culzean field was discovered in December 2008 by Maersk Oil, which was later acquired by TotalEnergies in August 2018.
The development plan was approved by the UK Oil and Gas Authority in August 2015. Installation of the facilities began in 2016, and production commenced in June 2019.

TotalEnergies is the operator with a 49.99% stake.
The other partners are BP (32%) and JX Nippon (now known as NEO Energy, with an 18.01% stake).

The Culzean field is a high-pressure, high-temperature (HPHT) gas condensate field, with estimated reserves between 250 million and 300 million barrels of oil equivalent.
The field can produce up to 100,000 barrels of oil equivalent per day (boe/d) and can meet around 5% of the UK’s total gas demand. At peak, it can produce 400 to 500 million standard cubic feet per day of gas.

The project includes three platforms: a Wellhead Platform (WHP) for drilling and hydrocarbon production, a Central Processing Facility (CPF) for processing and exporting gas and condensate, and a Utilities and Living Quarters (ULQ) platform for the crew.
The platforms are connected by two bridges, each about 100 meters long, which also feature walkways and support for power and communications cables.
A Floating Storage and Offloading (FSO) vessel named Ailsa is used for storing condensate. The FSO has a receiving capacity of 25,000 barrels per day and can store up to 430,000 barrels. It was delivered in 2018 and can operate for 25 years without dry-docking.

The CPF processes the gas to meet the Central Area Transmission System (CATS) entry specifications, and a 30km pipeline connects the Culzean facilities to the CATS pipeline. The gas is further processed at the CATS terminal to meet National Grid specifications at Teesside.
Associated condensate is carried via a 3km pipeline to the Ailsa FSO and is offloaded by shuttle tankers.

Culzean is noted for its advanced digital solutions, including a Support and Monitoring of Assets in Real Time (SMART) room for data collection, production management, and maintenance. The crew uses hand-held devices for real-time information and emergency response.
The project utilized efficient drilling techniques and supply chain optimization, reducing the initial budget by $500 million (10% of the initial estimate). A virtual reality model was used during the design phase to assess risks and optimize infrastructure.

TotalEnergies is implementing several decarbonization initiatives. In 2024, a pilot project was announced to install a floating wind turbine to supply renewable electricity to the Culzean platform, aiming to cover approximately 20% of the platform's electricity needs by the end of 2025.
Repairs and optimizations have also reduced flaring emissions by 40% and saved 3 million standard cubic meters of fuel gas per year, avoiding 6,000 tonnes of CO2 emissions annually.

Key contractors involved include KBR for front-end engineering and design (FEED) of the topsides, INTECSEA for subsea FEED, SMOE for fabrication of the platforms, MODEC for the engineering, procurement, and construction (EPC) of the FSO, and SOFEC for the design and supply of the internal turret mooring system for the FSO.
The project required more than 7,000 people and 40 million man-hours to complete.

The Culzean field has a design life of more than 20 years and is expected to remain operational beyond 2030.
The field's production capacity has been increased through technological improvements, reaching production levels of 550 million cubic meters of gas per day by June 2022.