The Indefatigable gas field is a large natural gas and associated condensate field located under the North Sea 60 miles (98 km) off the Norfolk coast.
The field The Indefatigable gas field is a natural gas field located in the North Sea. The field is 67 miles (107 km) north-east of Great Yarmouth and is named after the Indefatigable Banks, a shallow sand bank beneath which it is situated. The gas reservoir is a Rotliegendes sandstone 200–300 feet (61–91 m) thick at a depth of 8000–9000 feet (2440–2740 m). It was discovered in June 1966 and extends over several blocks: 49/18, 49/19, 49/23 and 49/24. The original determination of the gas in place amounted to 126 billion cubic metres. Blocks 49/18 and 49/23 were originally licensed to Amoco (since 2003 to Perenco UK Limited) and Block 49/19 and 49/24 to Shell. Production from the field began in September and October 1971. Gas and associated condensate are produced via the Leman gas field to the Bacton Gas terminal, Norfolk.
The Indefatigable gas composition and properties are as follows. Composition%Methane91.8Ethane3.39Propane0.85i-butane0.16n-butane0.20i-pentane0.07Hexanes0.06Heptanes plus0.16Nitrogen2.73Carbon dioxide0.52Hydrogen sulfideNilGas gravity0.61 %Mean condensate content3.0 bbl/million cubic footBtu rating1015 Btu/cubic foot
Baird gas field The Baird gas field is located in Block 49/23 and is licensed to Perenco (originally Amoco). It was discovered in September 1993 and has recoverable reserves of 1.82 billion cubic metres. Gas is produced via a seabed well assembly and a pipeline to Inde 49/23 D. The peak production was 0.66 billion cubic metres per year.
Development The Indefatigable field has been developed through a number of offshore installations.
The Inde installations developed by Amoco, now owned by Perenco, were: +Perenco (former Amoco) Inde installationsInstallationLocation BlockPlatformsFunctionTypeLegsWell slotsInstalledProduction startProduction toInde A Complex49/18Inde ADDrillingSteel jacket812July 1970September 1971Inde ATInde APProductionSteel jacket8–1970September 1971Inde B Complex49/18Inde BDDrillingSteel jacket8121973June 1974Inde ATInde BPProductionJackup4–1973June 1974Inde C Complex49/23Inde CDDrillingSteel jacket812August 1976July 1977Inde ATInde CPProductionSteel jacket8–1976July 1977Inde Compression49/23Inde ATPipeline terminalSteel jacket6–May 1971September 1971Leman 49/27BInde ACCompressionSteel jacket12–Jacket June 1979, topsides Summer 1980November 1980–Inde AQAccommodationSteel jacket4–June 1979––Inde D29/23Inde DWellheads and productionSteel jacket4419901990Inde C The Perenco Indefatigable 49/23A complex also receives gas from other fields and third parties:
Bessemer (49/23E) installation and its satellite N.W. Bell (49/23-9) via a 14.5 km 16-inch pipeline. Wenlock (49/12A) installation owned by Alpha Petroleum via a 36.231 km 8-inch pipeline. A three well-slot installation was installed in the Wenlock field in 2006 with wells commissioned in 2007, 2008 and 2009. Production declined quickly and make the installation uneconomic and a Decommissioning Programme application was submitted to the Oil & Gas Authority in 2021. Davy (49/30A) installation and its satellites Davy North (49/30A-7A) and Davy East (53/5B-7) via a 43 km 16-inch pipeline.
The Inde installations developed by Shell were: +Shell Inde installationsInstallationLocation BlockPlatformsFunctionTypeLegsWell slotsInstalledProduction startProduction toInde J Complex49/24Inde JDDrilling/productionSteel jacket86June 1970, April 1971September 1971Inde ATInde JPSatellite (accommodation)Steel jacket4–April 1972––Inde K Platform49/24Inde KDrilling/production/ accommodationSteel jacket106July 1971, June 1972March 1973Inde ATInde L Platform49/24Inde LDrilling/productionSteel jacket66February 1977October 1978Inde KInde M Platform49/19Inde MDrilling/productionSteel jacket44Spring 1985October 1985Inde JInde N PlatformInde NDrilling/productionSteel jacket441980'sInde K Production from the Shell Inde field ceased in 2005, Inde J, K, L, M, and N were subsequently decommissioned and removed.
Production
See also Leman gas field Hewett gas field West Sole gas field Viking gas field Sean gas field Davy, Bessemer, Beaufort, Brown and Boyle gas fields
References