The L4-L7 gas fields are significant natural gas producing fields in the Netherlands sectors L4 and L7 of the North Sea. They are operationally one complex which started producing gas from the L7 main platform hub in 1977 and was still partly operational in 2021.

The fields The adjacent Block L4 and L7 gas fields are located in the Southern North Sea. The L7 gas field was discovered in 1973 and the L4 field the following year. The gas reservoirs are Upper Rotliegendes sandstones, L7 lies at a depth of . The L7 field had recoverable reserves of 1.47 trillion cubic feet.

Development The L4-L7 reservoirs were developed by a number of offshore installations across both Blocks. The L7 main platform complex was the hub of the fields, it received gas from its bridge-linked drilling/wellhead (C) and compression (PK) platforms, from L7 Block satellite platforms, and from the adjacent Block L4. +L4-L7 Fields Offshore installationsInstallationCoordinatesWater depth PlatformFunctionTypeLegsWell slotsInstalledProduction startProduction toStatusL7 main platform complex (bridge linked)53°32’18”N 04°12’9”E27.5 mL7-C PlatformDrilling, productionSteel jacket46April 1976June 1977L7-PClosedL7-P PlatformProcessingSteel jacket8–1976June 1977L10 platform by 5.8 km 16-inch pipelineClosed May  2017L7-Q PlatformAccommodationSteel jacket4–1976––ClosedL7-PK PlatformCompressionSteel jacket4–June 19821983L7-PClosed May 2017L7B Complex53°36’32”N 04°12’24”E34.7 mL7-B PlatformDrilling, productionSteel jacket46July 19751977L7-P by 7.85 km 12-inch pipelineClosedL7-BBWellhead platformSteel jacket46September 19781979ClosedL7A Satellite53°36’01”N 04°05’01”E34.5 mL7-A PlatformDrilling, productionSteel jacket42August 1984Late 1985L7-P by 9.8 km 10-inch pipelineClosedL7-H53.626389°N 4.144967°E36 mL7-H PlatformWellhead platformFixed steel1989ClosedL7-N53.573944°N 4.176776°E32 mL7-N PlatformWellhead platformFixed steel1988Wells plugged 2015L4-A53°43’32”N 04°05’56”E39.5 mL4-A PlatformDrilling, production, accommodationSteel jacket86Summer 19821983L7-P by 22.7 km 12-inch pipelineOperatingL4-B53°40’36”N 04°00’06”E38.7 mL4-B PlatformDrilling, productionSteel jacket42August 1984Late 1985L7-A by 10.6 k, 10-inch pipelineWells plugged 2015L4-G53.81009°N 4.15805°E42 mL4-GWellheadSubsea wellhead2006OperatingL4-PN53.82341°N 4.0498°E41 mL4-PN PlatformProductionFixed steel1998Operating

The peak production from the L7 field was 135 MMSCFD in 1978–9, and from the L4 field was 106 MMSCFD in 1983. The design capacity of the process facilities on L7-P platform is 5.5 million m3/day.

The field was initially operated by Petroland BV, then Total.

Decommissioning The status of the production facilities is given in the final column of the above table. The entire L7 field is now closed as is the L4-B Platform. Operations continue in parts of the L4 field.

See also

Helder, Helm and Hoorn oil fields Kotter and Logger oil and gas fields K13 gas fields K14-K18 gas fields L10 gas field

References