# K7-K12 gas fields

The K7-K12 gas fields are significant natural gas producing areas in the Netherlands sector of the North Sea, about 130 km west of Den Helder. These six contiguous fields started producing gas in 1978 and are mostly still operational in 2021.

## The fields

The K7-K12 gas fields are located in the Southern North Sea. They extend over the Netherlands Blocks K7, K8, K9, K10, K11 and K12. The gas reservoirs have the following properties:
K7-K12 field gas reservoir properties :
| Block | K7 | K8 | K9 | K10 | K11 | K12 |
| Producing horizon | Rotliegendes | Rotliegendes | | Rotliegendes | Rotliegendes | Rotliegendes |
| Depth, metres | 3,150 | 3,300 | | 2,770 3,080 | 3,160 | |
| Type of gas | High calorific value (CV) | High CV | | | High CV | High CO$_2$ |
| Recoverable reserves, billion cubic feet | 247 | 720 | | | 189 | 200 |
| Discovery | 1969 | 1970 | | 1973 and 1979 | 1971 | 1976 |
| Initial operator | Nederlandse Aardolie Maatschappij BV (NAM) | Nederlandse Aardolie Maatschappij BV (NAM) | Gaz de France | Pennzoil | NAM | Placid |
| Subsequent operators | | | Neptune Energy, Engie E&P Nederland | Wintershall | Gaz de France | Gaz de France |

## Development

The K7-K12 reservoirs were developed by a number of offshore installations across the Blocks.
K7-K12 Field Offshore installations :
| Field | Coordinates | Water depth | Installation designation | Function | Type | Legs | Well slots | Installed | Production start | Production to |
| K7 | 53°34’22”N 03°18’18”E | 36.1 | K7-FA1 Drilling | Wellhead | Steel jacket | 4 | 9 | April 1982 Deck | October 1982 | Production platform, bridge linked |
| K7 | 53°34’22”N 03°18’18”E | 36.1 | K7-FA1 Production | Processing, accommodation | Steel jacket | 6 | Nil | April 1982 Deck | | K8-FA1 |
| K7 | 53.55142N 3.26727E | | K7-FD1 | Satellite | Steel jacket | 4 | | 1998 | | |
| K7 | 53.50125N 3.37038E | | K7-FB1 | Satellite | Steel jacket | 4 | | 2003 | | |
| K8 | 53°30’00”N 03°22’13”E | 31.2 | K8-FA1 | Drilling, production, accommodation | Steel jacket | 10 | 12 | July 1977 Deck | March 1978 | K14-FA1 |
| K8 | | | K8-FA1-P | Accommodation | Steel jacket | | | 2001 | | |
| K8 | 53°30’55N 03°22’13”E | 31 | K8-FA2 | Drilling, | Steel jacket | 4 | 9 | October 1977 | September 1979 | K8-FA1 |
| K8 | 53°32’32N 03°25’25”E | 35 | K8-FA3 | Satellite | Steel jacket | 6 | 9 | May 1985 | 1985 | K7 |
| K9 | 53.52193N 3.99382E | 29.6 | K9ab-A | Satellite | Steel jacket | | | | 1987 | |
| K9 | 53.55295N 3.78426E | 28.4 | K9ab-B | Satellite | Steel jacket | | | | 1999 | |
| K9 | 53.65442N 3.87426E | 38. | K9c-A | Satellite | Steel jacket | | | | 1987 | |
| K10 | 53.363714N 3.253964E | 25, 29 | K10-BD Wellhead | Wellhead | Steel jacket | 6 | 12 | July 1982 Deck | January 1983 | Production platform, bridge linked |
| K10 | 53.363714N 3.253964E | 25, 29 | K10-BP Production | Processing, accommodation | Steel jacket | 6 | Nil | August 1982 | | K13-C |
| K10 | 53.404257N 3.288094E | 29 | K10-C | Satellite | Steel jacket | 4 | 6 | July 1982 | August 1983 | K10-B |
| K11 | 53°26’58N 03°20’34”E | 29.4 | K11-FA1 | Wellhead drilling | Steel jacket | 4 | 3 | 1980 | Mar 1980 | K8-FA1 |
| K12 | 53°28’36N 03°47’19”E | 29.5 | K12-A | Wellhead | Steel Jacket | 4 | 6 | July 1983 | September 1983 | L10-A |
| K12 | 53°27’33N 03°54’21”E | 27.4 | K12-C | Satellite wellhead | Steel jacket | 4 | 6 | September 1984 | October 1984 | |
| K12 | 53.34304N 3.89692E | 26.5 27.4 | K12-BD | Satellite wellhead | Steel jacket | | | | 1983 | |
| K12 | 53.34238N 3.8973 | 26.5 27.4 | K12-BP | Production | Steel jacket | | | | 1981 | |
| K12 | 53.460784N 3.905925E | 26.5 27.4 | K12-CC | Compression | Steel jacket | | | 1994 | | Bridge link to K12-BP |
| K12 | 53.42354N 3.88651E | 29.5 | K12-D | Satellite wellhead | Steel jacket | | | | 1985 | |
| K12 | 53.35712N 3.98373E | 26 | K12-G | Satellite | Steel jacket | | | 2001 | | |
| K12 | 53.25221N 3.31354 E | 26 | K12-K | Wellhead platform | Steel jacket | | | 2006 | 2007 | |
| K12 | 53.4218N 3.825E, 53.34694N 4.9475E | ?, 26, 46 | K12-S1, K12-S2, K12-S3 | Subsea wellheads | Subsea wellhead | – | | 1991, 2002, 2003 | | |
The principal pipelines in the fields are:
K7-K12 Fields pipelines :
| Start | End | Length, km | Diameter, inches | Fluid |
| K7-FA1 | K8-FA1 | 9.4 | 18 | Gas |
| K8-FA1 | K14-FA1 | 30.9 | 24 | Gas |
| K8-FA2 | K8-FA1 | 3.8 | 10 | Gas |
| K8-FA3 | K7 | 9 | 12 | Gas |
| K10-B | K13-C | 7.4 | 20 | Gas |
| K10-C | K10-B | 5.2 | 10 | Gas |
| K10-C | K10-B | 5.2 | 2 | Methanol |
| K11-FA1 | K8-FA1 | 6 | 6 | Gas |
| K12A | L10A | 30 | 14 | Gas |
| K12A | L10A | 30 | 2 | Methanol |
| K12C | K12A/L10A line sidetap | 0.4 | 10 | Gas |
| K12C | K12A/L10A line sidetap | 0.4 | 2 | Methanol |
| K12B | L10A | 22 | | Gas |
| K12B | L10A | 22 | | Methanol |
| K12C | K12C | 4.5 | 10 | Gas |
| K12C | Sidetap | 4.3 | 2 | Methanol |

## Production

Peak production from the fields was as follows:
K7-K12 Fields Production :
| Field | Production million m$^3$/day |
| K7-FA1 | 6 |
| K8-FA1 | 9.2 |
| K8-FA2 | 6 |
| K8-FA3 | 3.5 |
| K11-FA1 | 1.1 |
| K12-A | 2.7 |
| K12-C | 2.7 |

## Decommissioning

The K10 and K11 installations are now closed and have been decommissioned.