Banff

Banff Oil Field Project Profile

Location

The Banff oil field is located in the Central North Sea, approximately 25 kilometers southeast of the Gannet accumulations and 200 kilometers east of Aberdeen, UK. It spans across blocks 29/2a, operated by Canadian Natural Resources (CNR), and extends into block 22/27a, which was previously operated by Ranger.

Geology and Reservoir

The Banff field's reservoir is situated between 4,500 and 7,600 feet below the seabed. It consists of Palaeocene sands underlying a steeply dipping and faulted Upper Cretaceous (Maastrichtian) chalk formation, located around a salt diapir piercement. The reservoir is characterized as a high porosity, low permeability chalk formation.

Reserves and Production

Initially, the field was estimated to have reserves of about 60 million barrels of 38-39° API gravity oil and approximately 39 billion cubic feet of gas. Later estimates in 2007 indicated recoverable reserves of 6.7 million tonnes of oil and 0.61 billion cubic meters of gas. Current production is around 10,000 barrels of oil per day (b/d) and 35 million cubic feet per day (MMcf/d) of gas.

Development and Infrastructure

The Banff field is developed using a unique floating production, storage, and offtake (FPSO) system. This FPSO is based on the Ramform hull design, which is the first of its kind to be used for this purpose. The FPSO is owned and operated by Petroleum Geo-Services UK Limited (PGS), with production operations sub-contracted to Atlantic Power. The subsea wells are tied back to a five-well cluster manifold, and the field also includes a gas-export pipeline that ties into the 36-inch CATS trunkline.

Drilling and Wells

After the initial exploration well, two appraisal wells (29/2a-7 and 29/2a-10) were drilled in 1991 and 1993, respectively. Production is from two horizontal production wells (29/2a-B1 and 29/2a-B2), which were drilled using the semisubmersible drilling rig Glomar Arctic III. These wells encountered more than 3,000 feet of hydrocarbon-bearing section in the chalk reservoir.

Production History

Production at Banff began in February 1999, with initial rates ranging between 6,000 and 34,000 b/d for the first three days. However, production was halted temporarily in 2000 due to operational issues with the leased Ramform FPSO, which was removed for repairs and refitting. Production restarted in March 2001. A natural gas reinjection program to enhance reservoir recovery was initiated in the fourth quarter of 2004.

Ownership and Operation

As of the latest updates, Canadian Natural Resources (CNR) holds a significant majority interest in the Banff field. In October 2003, CNR took over Conoco’s share of interest, and by 2023, CNR had agreed to purchase ConocoPhillips' 31.7% interest, raising its stake to 87.6%. This aligns with CNR's strategy of securing near-outright control of its North Sea properties.

Export and Logistics

Oil from the Banff field is exported via a double-hulled shuttle tanker in 500,000-barrel loads. The gas is exported through an 8-kilometer, 6-inch pipeline that ties into the 36-inch CATS trunkline.

Current Status and Future Plans

CNR is planning to revive the Banff field by reassessing the reservoir and exploring new synergies with the nearby Kyle field. The company aims to enhance recovery and potentially tie back other fields to the Banff FPSO. Recent stability issues with the vessel and concerns over reservoir producibility have been addressed, including the cessation of water injection and the installation of new bilge keels to improve stability.

In summary, the Banff oil field is a significant production asset in the Central North Sea, known for its unique FPSO design and challenging reservoir characteristics. It continues to be an important part of CNR's North Sea operations, with ongoing efforts to optimize production and extend the field's life.