The Morecambe gas fields are two major natural gas producing fields in Morecambe Bay in the Irish Sea, 27 km west of Blackpool.
| Morecambe South gas field | |
|---|---|
| Country | United Kingdom |
| Region | Irish Sea |
| Location/blocks | UK Block 110/2a and extends into Blocks 110/3a, 110/8a, 110/7a |
| Offshore/onshore | offshore |
| Coordinates | 53°50’48”N 03°34’51”W |
| Operators | Hydrocarbons GB Limited, British Gas E & P Ltd, Centrica plc, Spirit Energy |
| Owner | Hydrocarbons GB Limited, British Gas E & P Ltd, Centrica plc, Spirit Energy |
| Service contractors | see text |
| Field history | |
| Discovery | September 1974 |
| Start of production | January 1985 |
| Production | |
| Estimated gas in place | 150×109 m3 (5.3×1012 cu ft) |
| Producing formations | Triassic sandstone |
The fields edit
The Morecambe South field is in UK Block 110/2a and extends into Blocks 110/3a, 110/8a, 110/7a; Morecambe North is in Block 110/2a. The fields were discovered in September 1974 and February 1976 respectively.[1] [2] The fields are named after a light-ship station, they are sometimes erroneously called Morecambe Bay.[2]
The gas reservoir is a Triassic sandstone and has the following characteristics.[3] [4]
| Reservoir depth, feet | 2,200 to 3,750 |
| Gas column, feet | 1,650 |
| Porosity, % | 12-15 |
| Nitrogen content, % | 7-8 |
| Pressure at depth | 1,875 psi @ 3,750 feet |
| Recoverable reserves, trillion cubic feet (1985) | 5. 2 |
| Recoverable reserves South billion cubic metres (1994) | 150.0 / 5.2 Tcf |
| Recoverable reserves North billion cubic metres (1994) | 35.0 / 1.2 Tcf |
Owner and operator edit
In 1985 the sole licensee of the field and the operator was Hydrocarbons GB Limited.[3] This had become British Gas E & P Ltd by 1994, then Centrica plc in 1997. In 2017, Centrica launched Spirit Energy a joint venture with German energy and infrastructure company Stadtwerke München (SWM). Spirit Energy assumed ownership of the Morecambe gas fields.[5]
Development edit
The Morecambe gas fields development was to provide peak UK demand for gas in the winter. Morecambe South was developed around a central drilling, production and accommodation complex. This comprised three bridge linked platforms plus a bridge-linked flare tower. Details of the platforms are as shown.[3]
| Platform | CPP1 | AP1 | DP1 |
|---|---|---|---|
| Type | Steel jacket | Steel jacket | Steel jacket |
| Function | Central processing | Accommodation for 176 | Wellhead drilling |
| Coordinates | 53°50’48”N 03°34’51”W | 53.846667N 3.580556W | 53.846861N 3.580556W |
| Water depth, metres | 26 | 26 | 26 |
| Design contractors | Matthew Hall Eng. | Matthew Hall Eng. | Worley-Atkins |
| Topsides fabrication | Wm Press, Wallsend | ||
| Topside installation | March 1984 | June 1984 | 1985 |
| Jacket fabrication | RGC Offshore, Methil | RGC Offshore, Methil | McDermott, Ardesier |
| Jacket weight, tonnes | 11,754 | 4,100 | 5,500 |
| Jacket installation | October 1983 | March 1984 | April 1984 |
| Legs | 8 | 4 | 4 |
| Piles | 32 | 12 | |
| Wells | – | – | 16 (5-8 planned) |
| Startup | January 1984 | – | 1985 |
| Export to | Barrow, 39 km 36-inch pipeline | – | CPP1 via bridge |
The central complex Flare tower (53.846667N 3.580556W) is linked by a bridge to the CPP1 platform. It is supported by a 3-leg jacket.
In addition to the central DP1 drilling and wellhead platform, four other wellhead platforms were installed in the field, each producing well fluids to the CPP1 platform.[3]
| Platform | DP3 | DP4 | DP6 | DP8 |
|---|---|---|---|---|
| Type | Steel jacket | Steel jacket | Steel jacket | Steel jacket |
| Function | Wellhead drilling | Wellhead drilling | Wellhead drilling | Wellhead drilling |
| Coordinates | 53°49’00”N 03°33’37”W | 53°52’34”N 03°39’39”W | 53.867278N 3.616650W | 53.891872N 3.622833W |
| Water depth, metres | 30 | 30 | 32 | 32 |
| Accommodation | 6 | 6 | ||
| Design contractors | Worley-Atkins | Worley-Atkins | ||
| Topsides weight, tonnes | 5,200 | 5,200 | ||
| Topside installation | September 1983 | July 1984 | ||
| Jacket fabrication | McDermott, Ardesier | Howard Doris, Kishorm | ||
| Jacket weight, tonnes | 5,500 | 5,500 | ||
| Jacket installation | July 1983 | July 1984 | ||
| Legs | 4 | 4 | ||
| Wells | 16 (5-8 planned) | 16 (5-8 planned) | ||
| Startup | 1985 | 1985 | 1985 | 1985 |
| Export to | CPP1, 3.5 km 24-inch pipeline | CPP1, 3.5 km 24-inch pipeline | CPP1, 3.2 km 24-inch pipeline | CPP1, 5.8km 24-inch pipeline |
Because the gas reservoir is shallow, and to avoid a large deviation of the wells, slant drilling is used. Two jack up drilling rigs were built to undertake 30 degree slant drilling. The rigs were Morecambe Flame and Bay Driller.
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In 1984 a single drilling and production platform was installed in the Morecambe North field.[5] [6]
| Platform | Block | Coordinates | Water depth | Operational | Export |
|---|---|---|---|---|---|
| Morecambe North | 110/2a | 53.960578N 3.670694W | 29 metres | October 1994 | 37 km pipeline to Barrow |
The Bains field was developed in 2002 by a single subsea wellhead producing well fluids to DP1 via a 8.3 km 8-inch pipeline.[5]
The Bains field was developed in 2002 by a single subsea wellhead producing well fluids to DP1 via a 8.3 km 8-inch pipeline.[5]
| Field | Block | Coordinates | Water depth | Operational |
|---|---|---|---|---|
| Bains | 110/3c | 53.875833N 3.465556W | 18 metres | 2002 |
The North Morecambe platform was modified to tie in the Millom East / West and Dalton fields, and in 2013 the addition of the Rhyl field.[5]
Production edit
Well fluids from the wellhead platforms are piped to the CPP1 platform. Three phase separation into gas, condensate and water is undertaken. The gas is dehydrated using tri-ethylene glycol. Dry gas together with condensate is piped ashore.[3]
Initial production from Morecambe South field in the winter of 1984-5 was 120 million standard cubic feet of gas per day (MMSCFD). This increased to 450 MMSCFD in the winter of 1985-6 and ultimately to 1,200 MMSCFD.[3] The first year of peak production was 1993 when the South field produced 8.6 billion cubic metres per year.[1]
The first year of peak production for the Morecambe North field was 1995 when the field produced 3.1 billion cubic metres of gas per year.[1]
Decommissioning edit
The decommissioning of the DP3 and DP4 platforms is currently (2021) underway.[6] [7]
See also edit
References edit
- ^ a b c Department of Trade and Industry (1994). The Energy Report. London: HMSO. pp. 73, 74, Map 3. ISBN 0115153802.
- ^ a b More, Charles (2009). Black Gold. London: continuum. pp. 165–6. ISBN 9781847250438.
- ^ a b c d e f Oilfield Publications Limited (1985). The North Sea Platform Guide. Ledbury: Oilfield Publications Limited. pp. 526–39.
- ^ "The South Morecambe Gas Field, Blocks 110/2a, 110/3a, 110/7a and 110/8a, East Irish Sea". lyellcollection.org. Retrieved 6 November 2021.
- ^ a b c d e "Spirit Energy infrastructure" (PDF). spirit-energy.com. Retrieved 6 November 2021.
- ^ a b "South Morecambe DP3-DP4 Decommissioning Environmental Appraisal" (PDF). spirit-energy.com. Retrieved 6 November 2021.
- ^ "South Morecambe DP3-DP4 Decommissioning Programmes" (PDF). gov.uk. Retrieved 6 November 2021.