The Boulton Field, Block 44/21a, UK North Sea
The Boulton Field was discovered in 1984 when gas was tested from the Lower Ketch Unit, Carboniferous West-phalian C/D, in well 44/21-2. Following appraisal drilling in 1990, the Boulton ‘B’ structure was delineated and a trap confirmed by a combination of up-dip seal against basal Permian shales, and salts and lateral seal against sealing faults and impermeable Westphalian C sediments. A second structure was drilled in the same year, Boulton ‘F’, with gas discovered in the deeper Murdoch Sand Interval of the Westphalian C/D. The two separate structures collectively form the Boulton Field.
Current deliverability from the ‘B’ structure, Lower Ketch Sands is approximately 100 MMSCFD from a single producer. Developed with a minimal platform facility, the gas is delivered to Theddlethorpe Gas Terminal via offshore compression at the nearby Murdoch Field. The reservoir in Boulton ‘B’ comprises a series of channel sands deposited in a braided stream complex flowing predominantly from north to south across an Upper Carboniferous alluvial plain. Sandbody connectivity within the complex fluvial architecture of the Westphalian C is a key control on gas production.
Figures & Tables
Memoir 20 is the most comprehensive reference work on the UK’s oil and gas fields available. It updates and substantially extends Memoir 14 (1991), United Kingdom 0il and Gas Fields, one of the Geological Society’s best-selling books. This new edition contains updates on many of the ageing giant fields, as well as entries for fields either undiscovered or undeveloped when Memoir 14 was published.
The book is divided into nine parts covering the major petroleum provinces both offshore and onshore United Kingdom, from the Gas Basin in the southern North Sea to the Viking Graben in the northern North Sea, from the Atlantic Frontier to the Irish Sea and from the Wessex Basin to the East Midlands. Each part contains a reference map showing field locations. The introductory chapters reveal the stories behind the major plays and discoveries therein, and their tectonic and stratigraphic framework. There are two appendices: tabulated field data and a comprehensive list for all of the UK's 300+ oil and gas fields.