The Greater Markham Area gas fields are natural gas reservoirs and gas production facilities that straddled, or are close to, the UK and Netherlands median line of the southern North Sea. The UK field production facilities, which export gas to the Netherlands, began operation in 1992.
The fields
The Greater Markham Area gas fields are located in UK Blocks 49/4, 49/5, 49/9 and 49/10 and in Netherlands Blocks J3 and J6 of the southern North Sea. The fields are named: Markham, Windermere, Chiswick, Grove, Stamford and Kew.[1][2]
Markham
The Markham gas field was discovered by Ultramar in July 1984 with well 49/05-2. It is a lower Permian Leman/Slochteren sandstone, sourced from Carboniferous coal measures and is overlaid with Permian Silverpit claystone. It is a sweet gas with 83 % methane and a gas/condensate ratio of 9 barrels per million standard cubic feet (9 bbl/MMSCF) or 52.2 m3/106 m3. Recoverable reserves were estimated to be 700 Billion cubic feet (BCF) or 19.8 x 109 m3.[1] Ownership of the gas was established by the UK/Netherlands Markham Treaty as 37.40 % UK and 62.60 % Netherlands.[3]
The original licensee for Markham was a joint venture comprising Ultramar Exploration Ltd (89.50 %), DNO Offshore Ltd (8.00 %) and Ranger Oil (UK) Ltd (2.5 %.).[3] Ownership passed to CH4 Energy Ltd in 2003, Venture Production acquired ownership in 2006. Ownership eventually passed to Centrica, then in 2017 to Spirit Energy a joint venture of Centrica plc and Bayerngas Norge AS.[4]
Windermere
The UK Windermere gas field produced gas to Markham and hence to the Netherlands. Windermere is a Rotliegend-Leman sandstone discovered in 1989 by well 49/09b-2 by Mobil (who named the field Avalon)[3] and had an estimated gas in place of 104 BCF or 2.8 x 106 m3.[5]
Chiswick, Grove and Kew
The Chiswick and Kew are both Carboniferous fields Chiswick has gas in place of 687 BCF or 19.45 x 106 m3 and Kew 85 BCF or 2.41 x 106 m3.[6]
Development
The Greater Markham Area gas fields were developed in stages. Markham and Windermere gas fields were the first to be developed in 1994 and 1996. Gas was produced by two offshore installations, detailed in the table.[1][7]
Offshore platforms Markham and Windermere
Installation
Markham ST-1
Windermere
Blocks
49/5a and 49/10b (UK),
J3b and J6 (NL)
49/9b
Coordinates
53° 50.527’ N 02° 52.059’ E
53° 49.937’ N 02° 46.364’ E
Owner
Spirit Energy
Ineos UK SNS Ltd
Type
Normally unattended
Normally unattended
Water depth, metres
31
35
Installation date
1994
November 1996
Jacket type
Fixed steel
Fixed steel
Jacket legs
4
3
Jacket piles
4
3
Jacket weight, tonnes
888
382
Topsides dimensions, metres
26.3m x 22m
30m x 30m
Topsides weight, tonnes
1,300
452
Wellheads
6
2
Export to
Markham J6-A
Markham ST-1
Production start
November 1992
April 1997
The Chiswick, Grove, Kew and Stamford gas fields were developed over the period 2006-2014 by four offshore installations, detailed in the table.[1][2][8]
Offshore installations Chiswick, Grove, Kew and Stanford
Installation
Chiswick
Grove
Kew
Stamford
Blocks
49/4a
49/10a
49/4c
49/10c
Coordinates
53.939967 2.7740533
53.858778 2.886000
53.954935 2.784486
53.804192 2.836928
Owner
Spirit
Spirit
Spirit
Spirit
Type
Platform
Platform
Subsea wellheads
Subsea wellheads
Water depth, metres
40
30
41
34
Installation date
2006
2006
2014
2009
Jacket type
Fixed steel
Fixed steel
–
–
Jacket legs
–
–
Jacket piles
–
–
Jacket weight, tonnes
650
500
–
–
Topsides weight, tonnes
350
480
–
–
Wellheads
1
1
Export to
Markham J6-A
Markham J6-A
Chiswick
Markham J6-A
Production start
2006
2006
2014
2009
In addition to the platforms and subsea wells there were also gas and methanol pipelines and umbilicals in the Greater Markham area.[1]
Pipelines and Umbilicals
From – To
Country
Fluid
Diameter, inches
Length, km
Pipeline number
Markham ST-1 – Median line
UK
Gas
12
2.35
PL992
Median line – J6A
Netherlands
Gas
12
3.13
PL992
J6A – Median line
Netherlands
Methanol
2
3.127
PL993
Median line – Markham ST-1
UK
Methanol
2
2.347
PL993
Windermere – Markham ST-1
UK
Gas
8
6.8
PL1273
Markham ST-1 – Windermere
UK
Methanol
2
6.8
PL1273.1-3
Chiswick – J6A
UK, Netherlands
Gas
10
18.3
PL2353
J6A – Chiswick
UK, Netherlands
Methanol
1.5
18.3
PL2354
Grove – J6A
UK, Netherlands
Gas
10
13.4
PL2319
J6A – Grove
UK, Netherlands
Methanol
2
13.4
PL2320
Stamford – J6A
UK, Netherlands
Gas
6
7.5
PL2367
J6A – Stamford
UK, Netherlands
Methanol
7.5
PLU2368
Kew – Chiswick
UK
Gas
6
3.1
PL2974
Chiswick – Kew
UK
Methanol
3.1
PLU2975
Production
Gas production from Greater Markham Area fields is shown in the table and the graphs.[3][2][8]
Gas Production
Field
Production start
Peak flow, mcm/y
Peak year
Production ceased
Cumulative production to 2020 (mcm)
Markham
November 1992
933
1995
April 2016
7,877
Windermere
April 1997
438
1998
April 2016
2217
Chiswick
2007
569
2009
–
6915
Grove
2007
636
2010
–
3873
Kew
2014
175
2014
–
1053
Stamford
2009
132
2009
2013
165
The production profile, in mcm/y, of the Markham field was as shown.[8]
Graphs are unavailable due to technical issues. There is more info on Phabricator and on MediaWiki.org.
The production profile, in mcm/y, of the Windermere field was as shown.[8]
Graphs are unavailable due to technical issues. There is more info on Phabricator and on MediaWiki.org.
The production profile, in mcm/y, of the Chiswick field was:
Graphs are unavailable due to technical issues. There is more info on Phabricator and on MediaWiki.org.
The production profile, in mcm/y, of the Grove field was:
Graphs are unavailable due to technical issues. There is more info on Phabricator and on MediaWiki.org.
The production profile, in mcm/y, of the Kew field was:
Graphs are unavailable due to technical issues. There is more info on Phabricator and on MediaWiki.org.
The production profile, in mcm/y, of the Stamford field was:
Graphs are unavailable due to technical issues. There is more info on Phabricator and on MediaWiki.org.
Decommissioning
Spirit Energy submitted a Markham ST-1 decommissioning Programme to the Oil and as Authority in 2018.[1] Ineos Oil & Gas UK submitted a Windermere decommissioning Programme to the Oil and as Authority in 2018.[7] Decommissioning activities entailed plugging and abandonment of the wells and removal of all structures above the seabed.[1] The Markham topsides were taken to Lerwick Shetland for dismantling.