Britannia

Britannia Gas and Condensate Field Profile

Location and Geology

The Britannia field is located in the UK North Sea, specifically in blocks 16/26a, 16/27b, 15/30a, 15/29a, and 16/27c. The field is situated in shallow water with a depth of approximately 652 feet.

Ownership and Operation

Initially, the field was operated by Britannia Operator (BOL), a joint company formed by Chevron and Conoco, which were the majority shareholders. However, as of recent updates, the field is now operated by Chrysaor (U.K.) Britannia, and the ownership includes Delek Group, Harbour Energy, and HitecVision.

Development and Infrastructure

• Platform and Substructure: The project involves the installation of a large eight-leg jacket, which is one of the biggest ever built for North Sea operations. The jacket, weighing 20,000 tons and standing 160 meters tall, was constructed by Dragados Offshore in their yard in Puerto Real, Spain. The substructure is supported by 20 piles, each 123 meters long and 2.73 meters in diameter, driven 105 meters into the seabed.
• Topsides: The topsides include a 28,600-ton drilling, production, and accommodation platform, which is one of the top three heavy lifts in the UK. The installation of the 11,000-ton deck was a significant operation.
• Subsea Facilities: The field includes a 900-ton subsea manifold located 15 km from the platform, with three spare well slots. Pre-drilling of 18 wells commenced in May 1996, and an additional 27 wells were planned to start in spring 1998, aiming for a total of 45 wells to fully deplete the reservoir over 30 years.

Production and Reserves

• Reserves: The field has estimated reserves of 3.6 trillion cubic feet (tcf) of wet gas in place, 2.6 tcf of sales gas, and 143 million barrels of liquids. These figures were subject to revision as drilling progressed.
• Production: Peak production was achieved in 2000, and as of recent data, the field has recovered 92.07% of its total recoverable reserves. Production is expected to continue until the field reaches its economic limit in 2038. Currently, the field accounts for approximately 1% of the UK's daily gas output.

Cost and Efficiency

• Development Costs: The initial development cost target was significantly reduced through efficient pre-drilling programs and the decision to expand facilities at the SAGE processing complex onshore at St Fergus instead of building a dedicated terminal. This saved an estimated £100 million and brought the total development cost down by £500 million from the original target. The predicted development cost is £2.25 per barrel of oil equivalent (boe), with an overall cost including all activities since the first discovery in 1975 of below £6 per barrel.
• Operational Efficiency: The project aimed for high reliability and quality, ensuring the platform would last 30 years and be economical to operate. A drilling optimization review helped in reducing the total well costs from £443 million to £408 million.

Timeline

• Approval and Start: The project received approval from the UK's Department of Trade and Industry in December 1995 and was well underway by 1996.
• Key Milestones: The pre-drilling template was installed in April 1996, and pre-drilling of wells commenced in May 1996. The installation of the jacket and topsides was planned for subsequent years, with first gas production expected in the fourth quarter of 1998. Drilling of additional wells was scheduled to continue until spring 2004.

Safety and Environmental Considerations

• Safety Case: The field's safety case was close to being accepted by the UK's Health & Safety Executive, emphasizing high reliability and quality in operations.
• Environmental and Safety Responsibilities: Conoco handled conceptual engineering, safety, and environmental matters, as well as leading gas sales negotiations during the development phase.

The Britannia field is a significant gas and condensate development in the UK North Sea, marked by its large-scale infrastructure, efficient development strategies, and long-term production plans.