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Leman gas field

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Leman gas field
CountryUnited Kingdom
RegionNorth Sea
Block49/26
49/27
Offshore/onshoreoffshore
Coordinates53°04′56″N 2°10′05″E / 53.082184°N 2.168079°E / 53.082184; 2.168079
OperatorPerenco[1]
Field history
Discovery1966
Start of production1969
Production
Current production of gas5.7×10^6 m3/d
200×10^6 cu ft/d 2.1×10^9 m3/a (74×10^9 cu ft/a)
Estimated gas in place316×10^9 m3
11×10^12 cu ft

The Leman gas field is a natural gas field located in the North Sea 30 miles (48 km) northeast of Great Yarmouth, United Kingdom. Named after the Leman Sandbank beneath which it is situated, the gas reservoir is a 18 miles (29 km) long, 5 miles (8.0 km) wide,[2] 800 ft (240 m) thick Rotliegendes sandstone reservoir at a depth of about 6,000 ft (1,800 m).

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).[3]

Development

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The Shell Leman 49/26A (AD1, AD2, AP & AK) installation began production in August 1968. It had initial recoverable reserves of 292 billion m3.[4] 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:[5]

Leman 26AD2 North Sea offshore platform and other platforms in the Leman field
Shell Leman installations
Installation Location Block Platforms Function Type Legs Well slots Installed Production start Production to
Leman A Complex 49/26 Leman AD1 Drilling Steel jacket 12 20 June 1967 August 1968
Leman AD2 Drilling Steel jacket 4 3 September 1969 1970
Leman AP Production Steel jacket 12 August 1967 August 1968 Bacton, Leman BT
Leman AK Compression (900 MMSCFD) Steel jacket 8 February 1975 1975
Leman B Complex 49/26 Leman BD Drilling Steel jacket 12 24 June 1969 November 1970
Leman BP Production (500 MMSCFD) Steel jacket 8 December 1969 November 1970 Leman BT
Leman C Complex 49/26 Leman CD Drilling Steel jacket 12 20 1971 February 1972
Leman CP Production (650 MMSCFD) Steel jacket 8 1971 February 1972 Leman BT
Leman D platform 49/26 Leman D Drilling, production (500 MMSCFD) and accommodation Steel jacket 12 19 1971/3 September 1974 Leman BT
Leman E platform 49/26 Leman E Drilling, production (240 MMSCFD) and accommodation Steel jacket 6 10 January 1982 September 1983 Leman BP
Leman F platform 49/26 Leman F Drilling, production and accommodation Steel jacket Leman AP
Leman G platform 49/26 Leman G Drilling, production and accommodation Steel jacket Leman F
Leman BT BK BH Complex 49/26 Leman BT Field terminal Steel jacket 6 June 1970 Bacton
Leman BK Compression (900 MMSCFD) Steel jacket 8 February 1975 1975
Leman BH Accommodation Steel jacket 4 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.

Shell Leman 26A North Sea platform

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.[4] 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 installations
Installation Location Block Platforms Function Type Legs Well slots Installed Production start Production to
Leman A Complex 49/27 Leman AD Drilling Steel jacket 8 12 August 1967 Easter 1969 Leman AP
Leman AP Production Steel jacket 6 July 1968 Easter 1969 Leman AC
Leman AC Compression (900 MMSCFD) Steel jacket 8 1975 October 1976 Bacton
Leman AQ Accommodation Steel jacket 4 March 1984
Leman AX Compression (LP) Steel jacket 1988 1989 Leman AC
Leman B Complex 49/27 Leman BD Drilling Steel jacket 8 12 May 1968 Leman BP
Leman BP Production (171 MMSCFD) Steel jacket 6 August 1968
Leman BT Field Terminal Steel jacket 6 April 1970 Bacton
Leman C Complex 49/27 Leman CD Drilling Steel jacket 8 12 1967 1969
Leman CP Production (292 MMSCFD) Steel jacket 6 1967 1969 Leman AP
Leman D Complex 49/27 Leman DD Drilling Steel jacket 8 12 1972 1973
Leman DP Production (300 MMSCFD) Jack up 6 1973 1973 Leman BT
Leman E Complex 49/27 Leman ED Drilling Steel jacket 8 12 1972 1974
Leman EP Production (80-90 MMSCFD) Steel jacket 4 1974 1974 Leman AP
Leman F Complex 49/27 Leman FD Drilling Steel jacket 8 12 1973 1975
Leman FP Production (337 MMSCFD) Jack up 6 1975 1975 Leman BT
Leman G platform 49/27 Leman G Production (300 MMSCFD) Steel jacket 12 1985 October 1985 Leman BT
Leman H platform 49/27 Leman H Production (250 MMSCFD) Steel jacket 4 4 1984 1985 Leman J
Leman J platform 49/27 Leman J Production (250 MMSCFD) Steel jacket 4 4 1984 1985 Leman 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

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The Leman gas composition and properties are as follows.[5]

Composition %
Methane 95.05
Ethane 2.86
Propane 0.49
i-butane 0.08
n-butane 0.09
i-pentane 0.03
n-pentane 0.02
Hexanes 0.02
Heptanes plus 0.04
Nitrogen 1.26
Helium 0.02
Carbon dioxide 0.04
Hydrogen sulphide Nil
Total sulphur <0.5
Gas gravity 0.585%
Mean condensate content 1.13 bbl/cubic foot
Btu rating 1024 Btu/ cubic foot

The annual gas production from the Shell Leman field (in million standard cubic feet) was:[5]

The annual gas production from the Amoco Leman field (in million standard cubic feet) was:[5]

See also

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References

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  1. ^ "BP to Sell Southern North Sea Gas Package to Perenco | Press | BP Global". Archived from the original on 2015-08-15. Retrieved 2015-09-21.
  2. ^ Tiratsoo, E N (1972). Natural Gas. Beaconsfield: Scientific Press Ltd. p. 209.
  3. ^ Glennie, K.W. (2001). "Exploration activities in the Netherlands and North-West Europe since Groningen" (PDF). Netherlands Journal of Geosciences - Geologie en Mijnbouw. Retrieved April 3, 2024.
  4. ^ a b Cassidy, Richard (1979). Gas: Natural Energy. London: Frederick Muller Limited. p. 54.
  5. ^ a b c d The North Sea platform guide. Ledbury, UK: Oilfield publications Limited. 1985. pp. 454–501.