Cygnus gas field
The Cygnus gas field is a natural gas reservoir and gas production facilities in the UK sector of the southern North Sea. It is about 150 km of east of the Lincolnshire coast and started gas production in 2016.
| Cygnus gas field | |
|---|---|
| Country | United Kingdom |
| Region | North Sea |
| Location/blocks | 44/11a, 44/12a |
| Offshore/onshore | Offshore |
| Coordinates | 54°34’14”N 02°17’28”E |
| Operator | Neptune E&P UK Ltd |
| Owner | Spirit Energy (61.25 %) and Neptune Energy (38.75 %) |
| Field history | |
| Discovery | 1988 |
| Start of production | December 2016 |
| Production | |
| Recoverable gas | 760×109 cu ft (22×109 m3) |
| Producing formations | Permian sandstones, Carboniferous |
The field
The Cygnus field extends over UK offshore Blocks 44/11a and 44/12a. The field was discovered in 1988 by Marathon Oil.[1] The reservoirs are Permian Leman sandstone and Carboniferous sandstone formations and have recoverable reserves of 760 billion cubic feet.[1]
In 2019 the Cygnus gas field was jointly owned by Spirit Energy (61.25 %) and Neptune Energy (38.75 %), Neptune E&P UK Ltd operates the infrastructure.[1]
Development
Production from the field has been developed in stages. In the first stage gas was produced by wells on the Cygnus Alpha platform and then routed by pipeline to the Bacton Gas Terminal via the Esmond Transmission System.[1] The next stage entailed development of the north west part of the field produced from the Cygnus Bravo platform which was routed 7 km to the Cygnus Alpha installation.[1]
Details of the Cygnus field infrastructure are as shown.[1][2][3][4]
| Platform name | Cygnus A WHP | Cygnus A PU | Cygnus A QU | Cygnus B |
|---|---|---|---|---|
| Block | 44/11a | 44/11a | 44/11a | 44/12a |
| Installation type | Fixed Steel platform | Fixed Steel platform | Fixed Steel platform | Fixed Steel platform |
| Coordinates | 54°36’36”N 02°22’29”E | 54°34’14”N 02°17’28”E | 54°34’12”N 02°17’23”E | 54°35’59”N 02°11’46”E |
| Function | Wellheads | Processing and utilities | Accommodation and utilities | Wellheads |
| Crew | 66 | Unattended | ||
| First gas | December 2016 | August 2017 | ||
| Water depth, metres | 22.5 | 22 | 21.7 | 22 |
| Design | AMEC | |||
| Jacket fabrication | BiFab Methil | |||
| Jacket weight, tonnes | 1,858 | 3,146 | 1,958 | 2,194 |
| Topside fabrication | Heerema Hartlepool | BiFab | Heerema Hartlepool | |
| Topsides dimensions, metres | 23 x 23 x 10 | |||
| Topsides weight, tonnes | 1,474 | 3,911 | 2,960 | 2,753 |
| No. of legs | 4 | 8 | 4 | |
| No. of well slots | 10 | – | – | 10 |
| No. of Wells | – | – | ||
| Production to | Cygnus APU across bridge | Bacton via Esmond system | – | Cygnus A PU |
| Production capacity | 9.1×106 m3 (320×106 cu ft) per day | – | ||
| Pipeline length and diameter | – | 50 km, 610 mm | – | 7.28 km, 324 mm (12.75 in) |
| Pipeline Number | – | PL3088 | – | PL3086 |
Production
Cygnus gas has a minimum Wobbe Index of 46.6 to 46.8 MJ/m3. This is below the minimum specification for entry into the National Transmission System (47.2 MJ/m3). Cygnus gas en route to Bacton, commingles within the ETS pipeline with gas from Trent and Tors fields. The mixed gas arrives at Bacton with a minimum Wobbe index of 46.5 to 46.7 MJ/m3. If there is a reduction of gas flow from the other fields that deliver gas to Bacton then the output of Cygnus is constrained. To maintain Cygnus flow a temporary reduction of Wobbe Index from 47.2 MJ/m3 to 46.5 MJ/m3 at the NTS entry point at Bacton terminal was agreed in 2020.[5]
See also
References
- "Cygnus gas field development". www.nsenergybusiness.com. Archived from the original on 2021-03-02. Retrieved 22 December 2021.
- "Cygnus". www.spirit-energy.com. Archived from the original on 2018-08-14. Retrieved 22 December 2021.
- "Inventory of Offshore Installations". odims.ospar.org. Archived from the original on 2021-11-25. Retrieved 22 December 2021.
- "OGA interactive Maps". ogauthority.maps.arcgis.com. Archived from the original on 2019-01-26. Retrieved 22 December 2021.
- "Amendment to Network Entry Provision at Perenco Bacton Terminal" (PDF). www.gasgovernance.co.uk. Archived (PDF) from the original on 2021-12-23. Retrieved 23 December 2020.