# L10 gas field

The L10 gas field is a major natural gas producing field and hub in the Netherlands sector of the North Sea, about 65 km west of Den Helder. The field started producing gas in 1976 and was still operational in 2021.

## The field

The L10 gas field is located in the Southern North Sea. The field was discovered by Placid International Oil Limited in February 1970. The gas reservoir is an Upper Rotliegendes sandstone at a depth of 3,772 to 3,800 metres. The properties of the gas are:
L10 field typical gas properties :
| Gas composition and property | Value |
| Methane | 84.75 % |
| Carbon dioxide | 2.73 % |
| Nitrogen | 6.1 % |
| Hydrogen sulfide | Nil |
| Gross calorific value | 39.19 MJ/m$^3$ |

## Development

The L10 gas reservoir was developed by a number of offshore installations across the L10 Block. The L10-A complex is the hub of the field, it receives gas from its bridge-linked riser platform, from L Block satellite platforms, and from the adjacent Block 12.
L10 Field Offshore installations :
| Installation | Coordinates | Water depth | Platform | Function | Type | Legs | Well slots | Installed | Production start | Production to |
| L10-A Complex | 53°24’14”N 04°12’07”E | 28 m | L10-A Drilling Platform | Drilling, wellheads, accommodation | Steel jacket | 10 | 12 | November 1972 | 1976 | Bridge linked to L10-AP |
| L10-A Complex | 53°24’14”N 04°12’07”E | 28 m | L10-A Production Platform | Processing | Steel jacket | 8 | – | 1974 | 1976 | Uithuizen by 178 km 36-inch pipeline |
| L10-A Complex | 53°24’14”N 04°12’07”E | 28 m | L10-A Riser Platform | Risers | Steel jacket | 4 | – | | | Bridge linked to L10-AP |
| L10-A Complex | 53°24’14”N 04°12’07”E | 28 m | L10-AC Compression Platform | Compression | | | | 1987 | 1987 | Bridge linked to L10-AP |
| L10 -B Complex | 53°27’28”N 04°13’59”E | 27 m | L10-B Wellhead Platform | Drilling, wellhead, production | Steel jackets | 4 | 6 | 1974 | July 1975 | L10-A by 7.0 km, 14-inch pipeline |
| L10 -B Complex | 53°27’28”N 04°13’59”E | 27 m | L10-BB Wellhead Platform | Wellhead | Steel platform | 3 | 4 | July 1980 | | Bridge linked to L10-B |
| L10-C Platform | 53°23’38”N 04°12’08”E | 26.5 m | L10-C Platform | Drilling, production | Steel jacket | 4 | 6 | 1974 | August 1975 | L10-A by 1.1 km 10-inch pipeline |
| L10-D Platform | 53°24’35”N 04°12’54”E | 27.4 m | L10-D Platform | Wellhead | Steel jacket | 4 | 6 | 1977 | July 1977 | L10-A by 1.15 km 10-inch pipeline |
| L10-E Complex | 53°25’57”N 04°14’13”E | 29 m | L10-E Platform | Wellhead | Steel jacket | 4 | 6 | 1977 | 1977 | L10-A by 4.1 km 10-inch pipeline |
| L10-E Complex | 53°25’57”N 04°14’13”E | 29 m | L10-EE Platform | Wellhead | Steel platform | 3 | 4 | September 1984 | 1984 | L10-B to L10-A pipeline by 0.08 km 10-inch pipeline |
| L10-F Platform | 53°23’13”N 04°15’39”E | 26 m | L10-F Platform | Wellhead | Steel jacket | 4 | 6 | July 1980 | January 1981 | L10-A by 4.2 km 10-inch spur pipeline |
| L10-G Platform | 53°29’28”N 04°11’48”E | 27 m | L10-G Platform | Wellhead | Steel jacket | 4 | 6 | July 1984 | August 1984 | L10-B by 5 km 10-inch pipeline |
| L10-K Platform | 53°29’38”N 04°16’14”E | 27 m | L10-K Platform | Wellhead | Steel jacket | 4 | 6 | September 1984 | 1984 | L10-B by 4.8 km 10-inch pipeline |
| L10-L Platform | 53.337542N 4.377599E | 27.1 m | L10-L Platform | Wellhead | | | | 1988 | 1988 | L10-A |
| L10-M Platform | | | L10-M Platform | Wellhead | Steel platform | 4 | | 2000 | 2000 | L10-A |
| L10-S Subsea completions | | | L10-S1, S2, S3, S4 | Wellhead | subsea | – | 4 | 1988 (S1), 1997 (S2, S3, S4) | 1988, 1997 | L10-AP by 6-inch flowlines |
The L10-A complex also receives gas from K12-C/CC, K12-D, K12-G and K12-K platforms.
Gas from the field is transported through the 178 km, 36-inch diameter Noordgastransport pipeline from the L10-A Complex to Uithuizen. The design capacity of the 36-inch pipeline is 33 million cubic metres per day.
The field was initially operated by Placid International Oil Limited, then Gaz de France Suez, then by Neptune Energy.

## Decommissioning

In June 2020 Neptune Energy announced that it had decommissioned three platforms in the L10 Field. These were the satellite platforms L10-C, L10-D and L10-G.
In December 2020 Neptune Energy began a feasibility study into whether depleted gas fields near L10-A, L10-B and L10-E could be used to sequester carbon dioxide. The capacity of the reservoirs is around 120-150 million tonnes of CO$_2$ and the annual injection rate would be about 5-8 million tonnes per year.