Morecambe gas fields

Gas field

Morecambe South gas field

Location in North West England

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Location in England

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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 3°34′51″W﻿ / ﻿53.84667°N 3.58083°W﻿ / 53.84667; -3.58083
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| 150×10 ~~^~~ 9 m3 (5.3×10 ~~^~~ 12 cu ft)
Producing formations| Triassic sandstone

The Morecambe gas fields are two major natural gas producing fields in the Irish Sea, 27 km west of Blackpool and Morecambe Bay.

## 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]

Morecambe reservoir properties  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

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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

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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]

Morecambe South central complex platforms  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]

Morecambe South wellhead platforms  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.

Morecambe North (DPPA) offshore installation.

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

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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

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The decommissioning of the DP3 and DP4 platforms is currently (2021) underway.[6] [7]

## See also

[edit]

* Rampside gas terminal

## References

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1. ^ a b c Department of Trade and Industry (1994). The Energy Report. London: HMSO. pp. 73, 74, Map 3. ISBN 0115153802.
2. ^ a b More, Charles (2009). Black Gold. London: continuum. pp. 165–6\. ISBN 9781847250438.
3. ^ a b c d e f Oilfield Publications Limited (1985). The North Sea Platform Guide. Ledbury: Oilfield Publications Limited. pp. 526–39.
4. ^ "The South Morecambe Gas Field, Blocks 110/2a, 110/3a, 110/7a and 110/8a, East Irish Sea". lyellcollection.org. Retrieved 6 November 2021.
5. ^ a b c d e "Spirit Energy infrastructure" (PDF). spirit-energy.com. Retrieved 6 November 2021.
6. ^ a b "South Morecambe DP3-DP4 Decommissioning Environmental Appraisal" (PDF). spirit-energy.com. Retrieved 6 November 2021.
7. ^ "South Morecambe DP3-DP4 Decommissioning Programmes" (PDF). gov.uk. Retrieved 6 November 2021.