# Viking gas field

The Viking gas field is a group of natural gas and associated condensate fields located under the southern North Sea about 85 miles (136 km) from the Lincolnshire coast. The field was in production from 1972 to 2018.

## The field

The Viking gas field is a group of natural gas accumulations under the UK North Sea. The field is named after the area of the North Sea beneath which the field is located. The gas reservoir is a Rotliegendes sandstone of Lower to Middle Permian age, at a depth of 9,100–10,200 feet (2,773–3,110 m) with a thickness of 200–500 feet (61–150 m). The Viking structures run north-west to south-east and extend over Blocks 49/12, 49/16 and 49/17. The field was discovered in 1965 and production started in 1972. The original gas in place amounted to 79.3 billion cubic metres. Gas and associated condensate from Viking A and Viking B were both exported via the Viking A field through a 28-inch diameter pipeline to the Viking gas terminal (renamed the Theddlethorpe gas terminal in 1988), Lincolnshire.
The Victor, Victoria and Vixen fields are adjacent to Viking and production from these fields is routed through the Viking offshore facilities.
The Viking and Victor gas compositions and properties are as follows.
Viking and Victor gas properties :
| Composition | North Viking % | South Viking % | Victor |
| Methane | 89 | 89 | 91 |
| Ethane | 6 | 6 | 3.6 |
| Propane | 1.4 | 1.4 | 1.0 |
| Carbon dioxide | 2 | 2 | 2.5 |
| Gas gravity | 0.61 | 0.61 | 0.604 |
| Mean condensate content | 3–6 bbl/million cu ft | 3–6 bbl/million cu ft | 1.8 bbl/million cu ft |
| Calorific value | 1030 Btu/cu ft | 1030 Btu/cu ft | 1020 Btu/cu ft |

### Ownership

The field was originally licensed to Conoco UK Ltd, later ConocoPhillips. In 2019 Chrysaor assumed the ownership of Conoco-Phillips North Sea Assets. In March 2021 Chrysaor Holdings merged with Premier Oil to form Harbour Energy.

## Development

The Viking field was developed through a number of offshore installations. These are summarized in the following tables.
Viking offshore installations :
| Installation | Location Block | Facility | Function | Type | Legs | Well slots | Installed | Production start | Production to |
| Viking A complex | 49/12 | AD platform | Drilling | Steel jacket | 8 | 11 | December 1970 | August 1972 | Viking AP |
| Viking A complex | 49/12 | AP platform | Processing | Steel jacket | 8 | – | March 1971 | August 1972 | Theddlethorpe gas terminal |
| Viking A complex | 49/12 | AR platform | Pipeline risers | Steel jacket | 6 | – | July 1971 | 1972 | Viking AP |
| Viking A complex | 49/12 | AC platform | Compression | Steel jacket | 8 | – | June 1975 | February 1976 | Viking AP |
| Viking A complex | 49/12 | FD platform | Drilling | Steel jacket | 4 | 4 | July 1975 | July 1976 | Viking AD |
| Viking B complex | 49/17 | BD platform | Drilling | Steel jacket | 8 | 11 | May 1972 | August 1973 | Viking BP |
| Viking B complex | 49/17 | BP platform | Processing | Steel jacket | 8 | – | June 1972 | August 1973 | Viking AR |
| Viking B complex | 49/17 | BC platform | Compression | Steel jacket | 8 | – | June 1975 | July 1977 | Viking BP |
| Viking B complex | 49/17 | BA platform | Accommodation | Steel jacket | 4 | – | 1992 | – | – |
| Viking CD | 49/17 | CD platform | Drilling and processing | Steel jacket | 6 | 4 | February 1974 | December 1974 | Viking B |
| Viking DD | 49/17 | DD platform | Drilling and processing | Steel jacket | 8 | 4 | May 1974 | October 1974 | Viking B |
| Viking ED | 49/16 | ED platform | Drilling and processing | Steel jacket | 8 | 4 | October 1974 | November 1975 | Viking B |
| Viking GD | 49/17 | GD platform | Drilling and processing | Steel jacket | 6 | 4 | June 1975 | July 1977 | Viking B |
| Viking HD | 49/17 | HD platform | Drilling and processing | Steel jacket | 6 | 4 | July 1974 | April 1975 | Viking B |
| Viking KD | 49/12 | KD platform | Production | Steel jacket | 3 | 6 | 1998 | 1998 | Viking BD |
| Viking LD | 49/17 | LD platform | Production | Steel jacket | 3 | 6 | 1998 | 1998 | Viking BD |

### Satellite fields

The satellite fields which exported gas via the Viking B complex were:
| Installation | Location Block | Facility | Function | Type | Legs | Well slots | Installed | Production start | Production to |
| Victor JD | 49/22 | JD platform | Production | Steel jacket | 4 | 8 | June 1984 | September 1984 | Viking BD |
| Victor JM | 49/22 | Subsea well | Production | Subsea | – | | 1995 | 1995 | Victor JM |
| Victoria SM | 49/17 | Subsea well | Production | Subsea | – | | 2008 | 2008 | Viking BD |
| Vixen VM | 49/17 | Subsea well | Production | Subsea | – | 1 | 2000 | 2000 | Viking BD |

## Production

The annual gas production from the Viking field (in millions of standard cubic feet) was:
Export from the Viking B field was originally routed to the shore terminal via Viking AR. From 2009 export was re-routed to shore via the LOGGS installation.

## Decommissioning

The Viking A field (Viking North) was decommissioned as uneconomical in 1991. The A field platforms (except AR) were removed in 1993–4.
Viking CD, DD, ED, GD & HD ceased production in 2011–15, and were removed in 2017–18.
Theddlethorpe gas terminal was permanently shut-down in August 2018. Production from all connected fields ceased.