The Clyde oil field is a crude oil producing field in the UK sector of the North Sea, 290 km east-south-east of Aberdeen. Production of oil started in 1987 and the field is still operational (2021).

Clyde oil field
Clyde oil field is located in North Sea
Clyde oil field
Location of Clyde oil field
CountryUnited Kingdom
RegionNorth Sea
Location/block30/17b
Offshore/onshoreOffshore
Coordinates56°27′10″N 2°17′18″E / 56.4528°N 2.2883°E / 56.4528; 2.2883
OperatorsBritoil, BP, Talisman, Talisman Sinopec Energy, Repsol Sinopec
OwnerEsso, Shell, Britoil, BP, Talisman, Talisman Sinopec Energy, Repsol Sinopec
Field history
Discovery1978
Start of production1987
Production
Recoverable oil154 million barrels (~2.10×10^7 t)
Recoverable oil (million tonnes)17.7
Producing formationsJurassic sandstone

The field

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The Clyde oil field is located in Block 30/17b of the UK North Sea continental shelf. It is named after the Scottish river.[1] The Clyde field was discovered in 1978 and the oil reservoir comprises an Upper Jurassic sandstone at a depth of 10,000 feet (3,000 metres).[2] The reservoir and its fluids has the following characteristics:[2]

Clyde reservoir and fluids
Parameter Value
Porosity 0.23%
Permeability 105 md
API gravity 38.1°API
Gas Oil Ratio 477 standard cubic feet/barrel
Sulfur content 0.3%
Recoverable reserves 154 million barrels, 17.7 million tonnes

Owners and operators

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The initial owners of the field were Britoil (51%), Shell UK Ltd (24.5%) and Esso Petroleum Company Ltd (24.5%).[2] Britoil was the operator. BP assumed ownership of Britoil assets in 1988. BP sold its interest in Clyde to Talisman in 1996. The company became Talisman Sinopec Energy, then Repsol Sinopec.[3]

Development

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The Clyde field was developed by a single integrated drilling, production and accommodation platform. The principal design data of the Clyde platform is given in the following table.[2]

Clyde platform design data
Coordinates 56.452778N 2.288333E
Water depth, metres 80
Fabrication substructure John Brown Earl & Wright
Jacket weight, tonnes 12,300
Topsides design Humphreys & Glasgow
Topsides weight, tonnes 17,259
Function Drilling, production, accommodation
Accommodation (crew) 207
Type Steel jacket
Legs 8
Piles 26
Well slots 30 (23 production, 5 water injection)
Throughput oil, barrels per day (bpd) 60,000
Water injection, bpd 100,000
Platform installed Summer 1985, May 1986
Production started Late 1987
Oil production to Fulmar A by 9.85 km 16-inch pipeline
Gas production to Fulmar A by 9.85 km 16-inch pipeline

Processing

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Oil from the wellheads and subsea tie-ins is routed to the 1st stage 3-phase (oil, gas, water) separator. Oil then flows to the 2nd stage and 3rd stage separators operating at successively lower pressures. After metering the oil is pumped to the Fulmar A platform for storage and tanker loading.[4]

Produced water from the separators is treated in a degassing vessel and hydrocyclones to an oil-in-water concentration of less than 30 ppm prior to discharge overboard.[4]

Gas from the separators is compressed in the LP Compressor, Intermediate Pressure (IP) Compressor, HP Compressor and Export/Lift Compressor. There is also a gas dehydration plant. Gas in excess of that required for gas lift is exported to Fulmar A and then to the SEGAL system to St. Fergus terminal.

The fluid handling capability of the Clyde facilities in its latter years was as follows:[4]

Clyde processing capability
Clyde process facility Capacity
Crude oil export 60,000 bpd
Gas dehydration 42 MMSCFD
Produced water treatment 97,000 bpd
Water injection 73,000 bpd

Other fields

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Several subsea fields are connected to Clyde through flowlines and pipelines. These fields include Leven, Medwin, Nethan, Orion, Cawdor and Flyndre. There are dedicated Separators on Clyde for the Orion and Flyndre fields.[4] Data on these fields are as follows:[3][4]

Field Cawdor Flyndre Leven Medwin Nethan Orion
Block 30/14 30/13 30/17b 30/17b 30/17 30/18
Water depth, m 70 70 86.9 75
Reserves, million tonnes 10.5 million barrels 0.1 million Sm3 1.03 0.48
Production start 2017 1992 1994 2004 1999
Peak production, million tonnes per year 5,000 bpd 10,000 bpd 0.24 0.18 13.1 ton th
Pipeline 20.46 km 20 km 8.5-inch pipeline 16.3 km 10-inch pipeline

The Flyndre field is located in the Norwegian sector of the North Sea. Production began in March 2017.[5]

References

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  1. ^ Department of Trade and Industry (1994). The Energy Report. London: HMSO. pp. 39 and map 9. ISBN 0115153802.
  2. ^ a b c d Oilfield Publications Limited (1985). The North Sea Platform Guide. Ledbury: Oilfield Publications Limited. pp. 139–43.
  3. ^ a b "Clyde oil field". abarrelfull. Archived from the original on 2012-11-01. Retrieved 19 October 2021.
  4. ^ a b c d e "Clyde Infrastructure Code of Practice" (PDF). www.repsolsinopecuk.com. Archived (PDF) from the original on 2021-10-29. Retrieved 19 October 2021.
  5. ^ "Flyndre facts". norskpetroleum.no. Archived from the original on 2017-03-31. Retrieved 19 October 2021.