Caister Murdoch System
CountryUnited Kingdom
RegionNorth Sea
Location/blocks43/19, 44/17, 44/18, 44/19, 44/21, 44/23, 44/26, 44/28, 49/1
Offshore/onshoreOffshore
Coordinates54.268717N 2.323767E
OwnerConoco & Total originally
Field history
DiscoveryFrom 1968
Start of production1993
Abandonment2018
Production
Producing formationsTriassic sands and Carboniferous

The Caister Murdoch System (CMS) was a major natural gas collection, processing and transportation system in the UK sector of the southern North Sea. It comprised 11 platforms, 8 subsea wellhead completions and interconnecting pipelines centered about 155 km east of Flamborough Head Yorkshire. It operated from 1993 to 2018.

Background

The Caister Murdoch System (CMS) was originally conceived by Conoco (U.K.) Ltd. and Total Oil Marine plc to develop the Murdock and Caister gas fields. Caister had been discovered by Total in Block 44/23 in January 1968 in Triassic Bunter Sands. However, its remote location near the UK / Netherlands median line meant there was no infrastructure to support the export of gas.[1] The Caister Carboniferous gas field was discovered by Total in Block 44/23 in February 1985 and the Murdoch Carboniferous field by Conoco in Block 44/22 in August 1985. The discovery by Shell Oil of the Schooner Carboniferous gas field in Block 44/26 in December 1986 made the development of CMS viable.[1]

The hub of the CMS was the Murdoch installation which initially comprised just the Murdoch MD platform. The Caister platform, installed in 1993, was an unmanned satellite. Production from MD began in October 1993 and was through the 188 km 26” pipeline to the Theddlethorpe gas terminal (TGT) in Lincolnshire.[1] Conoco's Boulton field (1997) and Shell's Schooner and Ketch platforms were tied into the Murdoch system in 1996 and 1999 respectively. As wellhead pressures declined a compression platform Murdoch MC and an accommodation platform Murdoch MA were bridge linked to Murdoch MD. Other fields were tied in from 2000 to 2012.[2]

List

The locations, properties and late-life (2017) operatorship of gas fields tied into CMS were as follows.[3] [2]

CMS Fields
Field and installation Block Coordinates Water depth, metres Discovered Initial licensee Operator (2017)
Boulton BM 44/21a 54.243611 2.320833 42 1984 Conoco ConocoPhillips
Boulton HM 44/21 54.189297 2.210781 36 ConocoPhillips ConocoPhillips
Caister  CM 44/23a 54.2.3809 2.451269 41 January 1968; February 1995 Total ConocoPhillips
Cavendish RM 43/19a 54.478744 1.740211 18 1989 Britoil Ineos
Hawksley EM 44/17a 54.559028 2.491753 17 2002 Conoco ConocoPhillips
Hunter HK 44/23a 54.308500 2.420167 34 1992, 2005 Caledonia Premier
Katy KT 44/19b 54.403758 2.660611 26 2012 ConocoPhillips ConocoPhillips
Kelvin TM 44/18b 54.336577 2.258694 32 2005 ConocoPhillips ConocoPhillips
Ketch KA 44/28b 54.049417 2.488350 51 1984 Shell Faroe Petroleum (UK)
McAdam MM 44/17 54.346472 2.357472 32 2001 Conoco, Tullow ConocoPhillips
Munro MH 44/17b 54.434625 2.300146 27 2004 Tullow ConocoPhillips
Murdoch K KM 44/22a 54.238186 2.389775 38 Tullow ConocoPhillips
Murdoch MD 44/22 54.268717 2.323767 32 August 1985 Conoco ConocoPhillips
Murdoch MC 44/22 54.268611 2.323889 32 – – ConocoPhillips
Murdoch MA 44/22a 54.164250 2.191839 30 – – ConocoPhillips
Rita 44/22c 54.277023 2.210656 35 1996 E.ON Ruhrgas UK Premier
Schooner SA 44/26a 54.099033 2.076383 73 December 1986 Shell Faroe Petroleum (UK)
Topaz 49/1a 53.955167 2.827306 34 2009 RWE Dea Ineos
Watt QM 44/22 41 2001 Conoco ConocoPhillips

Names

The names of gas fields in the area are derived from several themes.[1]

Developments

The gas fields were developed through an array of platforms and subsea facilities. These were as shown in the following table, together with data on the peak rate and cumulative production of gas in million cubic metres (mcm).[4] [5] [2] [3]

CMS developments and production
Installation Structure Start-up Production to Pipeline length and diameter Peak production, mcm/y Year of peak Cumulative production to 2014, mcm
Boulton BM Steel jacket 1997 Murdoch MD 11 km, 10” 925 1998 7,185
Boulton HM Subsea 2002 Watt QM 140 2004 357
Caister CM Steel jacket 1993 Murdoch MD 11 km, 16” 388 (Bunter) 1995 3,202
745 (Carboniferous) 1995 5,156
Cavendish RM Steel jacket 2006 Murdoch MD via Cavendish manifold 47.2 km, 10” 649 2008 2,480
Hawksley EM Subsea 2002 Murdoch MD via manifold 22 km, 12” 610 2003 1,464
Hunter HK Subsea 2006 Murdoch K KM 6.2 km, 8” 24 2008 41
Katy KT Steel 3-legs 2012 Kelvin TM–Murdock MD pipeline 14 km, 10” 200 2013 200
Kelvin TM Steel 3-legs 2007 Murdoch MD via manifold 12.5 km, 12” 457 2008 738
Ketch KA Steel jacket 1999 Murdoch MD 28 km, 18” 1,233 2000 6,407
McAdam MM Subsea 2003 Hawksley–Murdoch pipeline 926 2006 3,691
Munro MH Steel 3-legs 2005 Hawksley EM 5 km, 10” 354 2006 1,379
Murdoch K KM Subsea 2002 Murdoch MD via manifold 5.5 km, 10” 1,378 2003 5,682
Murdoch MD Steel jacket 1993 Theddlethorpe 188 km, 26” 1,063 1994 13,606
Murdoch MC Steel jacket 1993 Murdoch MD – – – –
Murdoch MA Steel jacket 1993 – – – – –
Rita Subsea 2009 Hunter HK 14 km, 8” 506 2010 1,086
Schooner SA Steel jacket 1996 Murdoch MD 30 km, 16” 1,245 1997 8,659
Topaz Subsea 2009 Schooner SA 15.5 km, 6” 94 2010 198
Watt QM Subsea 2003 Murdoch MD via manifold 17 km, 10” 16 2004 16

In addition to the gas pipelines there was also a methanol distribution system. Methanol/corrosion inhibitor was pumped from TGT through a 4-inch pipeline to Murdoch MD. From here it was distributed to the platforms and wellheads through 3-inch and 2-inch pipelines.[6]

New pipeline reception facilities and process plant was installed at TGT as part of the CMS development.

Production

The production profile, in mcm/y, of the Murdoch field was as shown.[3]

Gas compression

Wellhead gas from the individual fields was routed to either the Suction, the Interstage or the Discharge Manifold on Murdoch MC depending on its pressure.[7]  Gas from the Suction Manifold was routed to the Suction Slug Catcher where liquids were removed. Gas flowed successively to the LP Suction Scrubber, the First Stage Gas Compressor and the Intercooler. Here it was comingled with gas from the Interstage Manifold which had flowed through the Interstage Slug Catcher. The combined flow was routed to the Interstage Scrubber, the Second Stage Gas Compressor and the Export Gas Cooler. Gas was returned to the MD platform and to the Theddlethorpe trunk line. Recovered liquids were injected into the trunk line.[7]

To increase the compression capacity a compressor module was added to the Murdoch MC platform in 2003.[8]

Telecommunications

Murdoch MD was connected to the Tampnet (formerly NorSea Com-1) submarine telecommunications cable system.[9] It has landing points at Lowestoft, Suffolk, UK and Kårstø, Rogaland, Norway. It is connected to:

1.      Draupner platform, operated by Gassco

2.      Ula oil field, operated by BP

3.      Ekofisk, operated by ConocoPhillips

4.      Valhall oil field, operated by BP

5.      Murdoch gas field, operated by ConocoPhillips (now disconnected)[9]

Decommissioning

Some CMS fields were shut-in in the 2010s when they became uneconomic to operate. Production from the CMS ceased with the shutdown of the Theddlethorpe gas terminal in August 2018. The platforms and subsea wellhead structures are being removed.[6]

See also

References

  1. 1 2 3 4 Department of Trade and Industry (2004). The Energy Report. London: HMSO. pp. 35, 75, 121, 125, Map 10. ISBN 0115153802.
  2. 1 2 3 "Inventory of Offshore Installations". OSPAR. Archived from the original on 2021-11-25. Retrieved 27 November 2021.
  3. 1 2 3 "Oil and Gas UK – Field data". Oil & Gas UK. Archived from the original on 2015-10-27. Retrieved 27 November 2021.
  4. ↑ "Caister Murdoch gas fields". abarrelfull. Archived from the original on 2014-06-26. Retrieved 27 November 2021.
  5. ↑ Conoco Gas Operations schematic Map (c. 2000)
  6. 1 2 "Caister Decommissioning Programmes" (PDF). Archived (PDF) from the original on 2021-05-05. Retrieved 27 November 2021.
  7. 1 2 Murdoch Compression Flow scheme (undated)
  8. ↑ "Caister Murdoch Phase 3". Archived from the original on 2003-02-19. Retrieved 24 November 2021.
  9. 1 2 "Tampnet".
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