Nexen Petroleum UK Ltd. has received approval from partners and the UK Oil & Gas Authority for second-phase development of Buzzard oil and gas field in the Central North Sea (OGJ Online, Nov. 1, 2017).
The new phase includes the installation in 96 m of water of a subsea manifold 5 km north of the Buzzard complex and drilling of as many as eight production wells and four water injectors.
The production wells will be completed subsea and tied back to the Buzzard production platform, one of four bridge-linked platforms on the field.
The field in April produced an average 134,660 b/d of oil. It has 35 production wells and 13 water injection wells.
The new phase is part of a plan to exploit expansion of Nexen’s estimate of original oil in place to 1.592 billion bbl from the original estimate of 970 million bbl.
Incremental development also will occur via the drilling of as many as six infill wells from Buzzard’s wellhead platform.
The field produces from the Buzzard sandstone of the Upper Jurassic Kimmeridge Clay formation.
In a high-case estimate assuming production start in 2020, peak incremental production from the subsea wells will occur in 2021 at 43,520 b/d. With infill wells, the maximum boost is 44,350 b/d.
Oil in the second phase is slightly lighter than that of existing production, at 39° gravity.
The new work is expected to delay Buzzard’s cessation of production by 10 years to 2046.
Nexen, a wholly owned subsidiary of CNOOC Ltd., operates Buzzard with a 43.21% interest. Partners are Suncor Energy UK Ltd., 29.89%; Chrysaor, 21.73%; Dyas Exploration UK Ltd., 4.7%; and Oranie-Nassau Energie Resources Ltd., 0.46%.
Second-phase work involves an integrated project team of Nexen; AGR Well Management Ltd.; Baker Hughes; COSL Drilling Europe AS; Subsea 7 Ltd.; and WorleyParsons Services UK Ltd.