Bittern

Bittern Oil and Gas Field Profile

Location

The Bittern oil and gas field is situated in the Central North Sea of the UK, specifically in Blocks 29/1a and 29/1b. It is approximately 190 km east of Aberdeen, Scotland, at a water depth of about 90 meters.

Discovery and Production

The field was discovered in 1995 (or 1996, according to some sources) and commenced production in April 2000. The field is part of the larger Triton area, which includes several other producing oil fields tied back to the Triton Floating Production Storage and Offloading (FPSO) unit.

Ownership and Operation

The field is operated by Dana Petroleum, a subsidiary of the Korea National Oil Corporation, which holds a 32.95% interest. The other partners are Serica Energy with a 64.63% interest, acquired from Tailwind Energy Holdings in March 2023, and Waldorf Production UK PLC with a 2.42% interest.

Field Details

• Geology: The field is located in a good quality Eocene reservoir and contains light 39°API oil with an initial gas cap.
• Infrastructure: The field is developed with five production wells and two water injection wells. It employs a subsea tie-back system to the Triton FPSO. The infrastructure includes two seven-slot manifolds, four 10-inch production wells, a 12-inch water injection pipeline, and a 4-inch gas lift pipeline. The water injection and gas lift pipelines connect the Triton FPSO to the Bittern field’s Drill Centre B manifold (DCB).

Production and Reserves

• Production: The field produces oil and gas, with oil exported via shuttle tanker and gas exported via the SEGAL gas line. In 2022, the gross production was up to 14,000 barrels of oil equivalent per day.
• Reserves: Specific reserve figures are not detailed in the recent sources, but the field has undergone several well interventions and sidetracks to maintain and enhance production.

Recent Developments

• New Drilling Program: A four-well program is scheduled to begin in 2024, including the Bittern B1z sidetrack (now designated as the B6 well), which has been drilled successfully. The well is set to be completed and tested in August 2024 following the Triton summer shutdown.
• Water Injection Pipeline: A new 22 km long, 12-inch water injection pipeline is to be installed. Project management and engineering works are scheduled to commence in Aberdeen in June 2024, with offshore activities planned for the third quarter of 2025. Subsea7 has been awarded the contract for this work, valued between $50 million and $150 million.

Triton FPSO

• Location and Operation: The Triton FPSO is located in Block 21/30, approximately 193 km east of Aberdeen. It operates in a water depth of 90 meters and is connected to several fields in the Triton area via subsea infrastructure.
• Specifications: The FPSO is 244 meters long, with a moulded breadth of 42 meters and a moulded depth of 21.3 meters. It has a deadweight of 105,000 tons and is equipped with a 42 MW power generation system. The FPSO has a storage capacity of 630,000 barrels and can process 105,000 barrels of oil per day, 140 million cubic feet of gas per day, and 125,000 barrels of water injection per day.
• Maintenance: The Triton FPSO underwent a shutdown from early July to mid-September 2023 for structural repairs and fabric maintenance to extend its life.

Contractors Involved

• Subsea7: Awarded a contract for the Bittern development, including the installation of the new water injection pipeline, associated subsea structures, and tie-ins at both the Triton FPSO and the Bittern field.
• COSL Drilling Europe: Operates the semi-submersible drilling rig COSLInnovator, which is used in the Triton area drilling campaign.