Frigg gas field
Frigg gas field is a natural gas field on Norwegian block 25/1 in the North Sea, on the boundary between the United Kingdom and Norway. The field is named after the goddess Frigg. King Olav V of Norway officially opened production on 8 May 1978. Production was closed on 26 October 2004. The field is situated northwest of Stavanger. Operator for the field was the French oil company Elf Aquitaine, which merged and changed name to Total S.A.
Operations were regulated according to an agreement between the UK and Norwegian governments called the Frigg Treaty.
Infrastructural changes were made in three phases:
The field was discovered at a depth of by the Petronord group and the Norwegian State in 1971 with Well 25/1-1 using the Semi-submersible Neptune P 81 in of water. The well was located following interpretation of a 15 by 20 km grid of Reflection seismology lines recorded in 1965. A 5 by 5 km finer grid of seismic lines were recorded in 1969, followed by a 1 by 1 km grid in 1973, which, combined with four appraisal wells, determined the field was in area with a gas column in Lower Eocene sandstones forming an abyssal fan in the Viking Structural basin. The fan structure appears on seismic sections as a low relief Anticline that includes a Flat spot caused by the Density contrast of the gas.
Development
The Frigg field has been developed through a number of offshore platforms.| Platform | Coordinates | Function | Type | Legs | Well slots | Installed | Production start | Production to |
| Frigg DP1 | 59°52’40”N 02°04’48”E | Drilling platform | Steel jacket | 8 | ? | October 1974 buoyancy tanks collapsed damaged beyond recovery | – | – |
| Frigg CDP1 | 59°52’31”N 02°03’42”E | Drilling, production | Concrete gravity | 1 | 24 | September 1975 | September 1977 | TP1 |
| Frigg TP1 | 59°52’47”N 02°03’51”E | Treatment | Concrete gravity | 2 | – | June 1976 | September 1977 | MCP01 |
| Frigg QP | 59°52’42”N 02°03’54”E | Quarters platform | Steel jacket | 4 | – | July 1975 | – | – |
| Frigg DP2 | 59°53’10”N 02°04’21”E | Drilling, production | Steel jacket | 8 | 24 | May 1976 | August 1978 | TCP2 |
| Frigg TCP2 | 59°52’48”N 02°04’01”E | Treatment, compression | Concrete gravity | 3 | – | June 1977 | August 1978 | MCP01, DP2 |
| Frigg MCP-01 | 58°49’39”N 00°17’12”E | Manifold, compression | Concrete gravity | 1 | – | June 1976 | September 1977 | St Fergus |
| Frigg flare platform FP | 59°52’54”N 02°03’21”E | Flare | Articulated steel | 1 | – | October 1975 | December 1977 | From TP1 |
| Frigg NE | 59°59’07”N 02°14’52”E | Field control station | Steel tower, concrete base | 6 subsea trees | June 1981 | December 1983 | TCP2 |
The initial production of gas was:
Pipelines
Pipelines associated with the Frigg field are as follows:| Start | Terminal | Length | Diameter | Type |
| TP1 / TCP2 | MCP-01 | 2 × 186 km | 32” | Gas |
| MCP-01 | St Fergus | 2 × 174 km | 32” | Gas |
| CDP1 | TP1 | 2 × 500 m | 26” | Gas |
| CDP1 | TP1 | 500 m | 4” | Condensate |
| TP1 | CDP1 | 500 m | 8” | Kill |
| DP2 | TCP2 | 2 × 700 m | 26” | Gas |
| DP2 | TCP2 | 700 m | 4” | Condensate |
| TCP2 | DP2 | 700 m | 8” | Kill |
| TP1 | FP | 500 m | 24” | Gas |
| TP1 | FP | 500 m | – | Gas air pilot |
| Subsea template | TCP2 | 18 km | 16” | Gas |
| TCP2 | NEF | 18 km | 1.25” | Methanol |
| FCS | Template | 500 feet | 2” | Kill |
Pipelines connected to the Frigg field
- Frigg UK System - natural gas transportation system from the Alwyn North Field in the North Sea via the Frigg field to St. Fergus near Peterhead in Scotland. The Frigg UK System is operated by Total E&P UK Plc.
- Vesterled - mostly the former Frigg Norwegian Pipeline.
- Gas production from the Odin gas field was transported to Frigg TCP2 by a 26 km 20-inch pipeline.
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