The Leman gas field is a natural gas field located in the North Sea northeast of Great Yarmouth, United Kingdom. Named after the Leman Sandbank beneath which it is situated, the gas reservoir is a long, wide, thick Rotliegendes sandstone reservoir at a depth of about .
Following its discovery in August 1966, the reservoir was divided into blocks 49/26 and 49/27 to facilitate the licensing of mineral rights. Block 49/26 has been licensed to Shell since the beginning, with Block 49/27 originally licensed to the Amoco-Gas Council joint venture before being transferred to Perenco UK Ltd. Production of natural gas and condensates began in 1968, with both products sent via pipeline systems to the Bacton Gas Terminal on the coast of Norfolk for international distribution.
The initial total proven reserves of the Leman gas field were around 11 trillion ft3 (316 km3), with a production rate of around 200 million ft3/day (5.7×105 m3).
Development The Shell Leman 49/26A (AD1, AD2, AP & AK) installation began production in August 1968. It had initial recoverable reserves of 292 billion m3. It is connected to the Shell terminal at Bacton. Leman 49/26B (BT & BH) and 49/26B (BP & BD) began production in November 1970. Leman 49/26C (CD & CP) began in February 1972. Leman 49/26D began in August 1974. Leman 49/26E started in August 1983. Leman 49/26F and 49/26G began in September 1987. The Leman complex of platforms are connected to Bacton via Leman 49/26A, which is east of the Hewett complex. A decommissioned 36-inch pipeline formerly delivered gas from Leman 49/26BT to Bacton. Gas and condensate is piped to Bacton via Leman 49/26A Complex (AK, AP, AD1 and AD2).
The installations developed by Shell were:
+Shell Leman installationsInstallationLocation BlockPlatformsFunctionTypeLegsWell slotsInstalledProduction startProduction toLeman A Complex49/26Leman AD1DrillingSteel jacket1220June 1967August 1968Leman AD2DrillingSteel jacket43September 19691970Leman APProductionSteel jacket12–August 1967August 1968Bacton, Leman BTLeman AKCompression (900 MMSCFD)Steel jacket8–February 19751975Leman B Complex49/26Leman BDDrillingSteel jacket1224June 1969November 1970Leman BPProduction (500 MMSCFD)Steel jacket8–December 1969November 1970Leman BTLeman C Complex49/26Leman CDDrillingSteel jacket12201971February 1972Leman CPProduction (650 MMSCFD)Steel jacket8–1971February 1972Leman BTLeman D platform49/26Leman DDrilling, production (500 MMSCFD) and accommodationSteel jacket12191971/3September 1974Leman BTLeman E platform49/26Leman EDrilling, production (240 MMSCFD) and accommodationSteel jacket610January 1982September 1983Leman BPLeman F platform49/26Leman FDrilling, production and accommodationSteel jacketLeman APLeman G platform49/26Leman GDrilling, production and accommodationSteel jacketLeman FLeman BT BK BH Complex49/26Leman BTField terminalSteel jacket6–June 1970BactonLeman BKCompression (900 MMSCFD)Steel jacket8–February 19751975Leman BHAccommodationSteel jacket4–February 1981––
The Shell Leman 49/26A complex also receives gas from the Corvette CV installation (Block 49/24) via a 36.6 km, 20-inch pipeline.
Block 49/27 of the Leman field is licensed to, and operated by, Perenco UK Ltd, originally by the Gas Council-Amoco. BP took over the interests of Amoco in 1998 and operated as BP-Amoco, subsequently BP. Perenco UK Ltd took over the interests of BP in the Leman and Indefatigable fields and BP plant at Bacton in 2003. The field had initial recoverable reserves of 292 billion m3. It comprises the following installations, platforms and complexes: Leman 49/27A (AD, AP, AC, AQ, AX); 49/27B (BD, BP, BT); 49/27C (CD, CP); 49/27D (DD, DP); 49/27E (ED, EP); 49/27F (FD, FP); 49/27G; 49/27H; and 49/27J. Gas is routed to Bacton via two 30-inch pipelines from Leman 49/27A and Leman 49/27B.
The Leman installations developed by Amoco, now owned by Perenco, were: +Amoco (now Perenco) Leman installationsInstallationLocation BlockPlatformsFunctionTypeLegsWell slotsInstalledProduction startProduction toLeman A Complex49/27Leman ADDrillingSteel jacket812August 1967Easter 1969Leman APLeman APProductionSteel jacket6–July 1968Easter 1969Leman ACLeman ACCompression (900 MMSCFD)Steel jacket8–1975October 1976BactonLeman AQAccommodationSteel jacket4–March 1984––Leman AXCompression (LP)Steel jacket19881989Leman ACLeman B Complex49/27Leman BDDrillingSteel jacket812May 1968Leman BPLeman BPProduction (171 MMSCFD)Steel jacket6–August 1968Leman BTField TerminalSteel jacket6–April 1970BactonLeman C Complex49/27Leman CDDrillingSteel jacket81219671969Leman CPProduction (292 MMSCFD)Steel jacket6–19671969Leman APLeman D Complex49/27Leman DDDrilling Steel jacket81219721973Leman DPProduction (300 MMSCFD)Jack up6–19731973Leman BTLeman E Complex49/27Leman EDDrillingSteel jacket81219721974Leman EPProduction (80-90 MMSCFD)Steel jacket4–19741974Leman APLeman F Complex49/27Leman FDDrillingSteel jacket81219731975Leman FPProduction (337 MMSCFD)Jack up6–19751975Leman BTLeman G platform49/27Leman GProduction (300 MMSCFD)Steel jacket121985October 1985Leman BTLeman H platform49/27Leman HProduction (250 MMSCFD)Steel jacket4419841985Leman JLeman J platform49/27Leman JProduction (250 MMSCFD)Steel jacket4419841985Leman A The Perenco Leman 49/27A complex also receives gas from the Camelot CA installation (Block 53/1a) via a 14.5 km, 12-inch pipeline.
In the mid-1990s the glycol dehydration facilities of several installations in the Inde and Leman fields was decommissioned. This enabled the installations to become normally unattended installations (NUIs) reducing manning costs and the risks to personnel.
Production The Leman gas composition and properties are as follows. Composition%Methane95.05Ethane2.86Propane0.49i-butane0.08n-butane0.09i-pentane0.03n-pentane0.02Hexanes0.02Heptanes plus0.04Nitrogen1.26Helium0.02Carbon dioxide0.04Hydrogen sulphideNilTotal sulphur<0.5Gas gravity0.585%Mean condensate content1.13 bbl/cubic footBtu rating1024 Btu/ cubic foot
See also Indefatigable gas field Hewett gas field West Sole gas field Viking gas field Arthurian gas fields Brigantine, Caravel, Corvette and Shamrock gas fields
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