The Beryl oil field is a major crude oil production field in the UK sector of the northern North Sea, 335 km north east of Aberdeen. Production of oil started in 1976 and the field is still producing oil and gas (2021).

Beryl oil field
Beryl oil field is located in North Sea
Beryl oil field
Location of Beryl oil field
CountryUnited Kingdom
RegionNorth Sea
Location/block9/13
Offshore/onshoreOffshore
Coordinates59°32′47″N 01°32′14″E / 59.54639°N 1.53722°E / 59.54639; 1.53722
OperatorMobil (to 2012), Apache (from 2012)
Ownersee text
Field history
Discovery1972
Start of production1976 (Beryl A), 1984 (Beryl B)
Production
Producing formationsSandstones

The field

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The Beryl oil field is located in Block 9/13a of the UK North Sea. It is named after Beryl Solomon wife of Charles Solomon the President of Mobil Europe at the time of the field’s discovery.[1] The Beryl field was discovered in May 1972 and is a Triassic and Jurassic sandstone at an average depth of 11,000 feet (3,353 m).[2] The reservoir and the fluids have the following characteristics:[2] [3]

Beryl reservoirs
Reservoir Porosity % Permeability md Water saturation % Net/Gross ratio %
Bruce 14 100 10 68
Upper Beryl 17 300 8 90
Middle Beryl 15 100 12 42
Lower Beryl 15 100 12 80
Lewis 15 20 30 50
Beryl reservoir fluids
Parameter Value
API gravity 36.5°API
Gas Oil Ratio 1,300 standard cubic feet/barrel
Sulfur content 0.3 %
Recoverable reserves Beryl A 500 million barrels
Recoverable reserves Beryl B 300 million barrels
Recoverable gas 1.6 trillion cubic feet

Owners and operators

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The Beryl field was originally licensed to partners comprising Mobil North Sea Ltd (50%), Amerada Hess (UK) Ltd (20%), Texas Eastern North Sea Inc. (20%), and Enterprise Oil Ltd. (10%).[2] Mobil was the Beryl field operator. In January 2012 the Apache Corporation acquired all the assets of Mobil North Sea and from then was the operator of the Beryl field with a 50% interest. The other owners are Hess Limited (22.22%), Enterprise Oil (22.78%) and OMV (UK) Ltd (5%).[4]

Development

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The field was initially developed in 1975 by a single integrated drilling, production and accommodation platform Beryl Alpha (or Beryl A) located in the south of the field.[2] Beryl A has oil storage compartments in the gravity base structure. Oil is exported from Beryl A through a pair of SPM (single point mooring) buoys located 2.0 km from Beryl A. Beryl Bravo (Beryl B) was installed in 1983 and located 8 km north of Beryl A to exploit the northern part of the oil field. Oil is exported from Beryl B to Beryl A through a 20-inch pipeline.[2]

As a ‘stranded asset’ with limited infrastructure gas was injected into the reservoir and the surplus was flared. From 1992 gas was exported via the 203 miles (327 km) 30-inch SAGE (Scottish Area Gas Evacuation) pipeline to St. Fergus.[1] In 1990 a riser tower was added to Beryl A to accommodate risers and gas compression equipment to export gas into SAGE.[5] The principal data of the Beryl field platforms is given in the following table.[2] [5]

Beryl field platforms
Installation Beryl A Beryl B Beryl Riser Access Tower (RAT)
Coordinates 59°32’47”N 01°32’14”E 59.610342N 1.512742E 59.545178N 1.535725E
Water depth, metres 117 120 117
Fabrication substructure Norwegian Contractors Stavanger RGC Methil
Fabrication topsides Aker Arendal Bechtel Middlesbrough & Cherbourg
Topside weight, tonnes 28,000 34,300
Function Drilling, production, storage, accommodation Drilling, production, accommodation Risers, compression
Accommodation 290 200
Type Condeep Steel jacket Steel jacket
Legs 3 8 4
Substructure 19 concrete fuel cells 32 skirt piles
Well slots 40 21 Nil
Throughput oil, bpd 300,000 (including B) 100,000
Throughput gas, MMSCFD 150 137
Oil storage capacity, barrels 900,000 Nil Nil
Gas injection, million m3/day 4.0 3.7
Water injection 100,000 bwd Nil Nil
Installed July 1975 May 1983 1990
Production start June 1976 July 1984 1990
Oil production to SPM buoys Beryl A Beryl A
Gas production to Flare, RAT SAGE SAGE

The Beryl partners had sanctioned the construction of Beryl B on the understanding that uplift on allowances against Petroleum Revenue Tax would be available for the expenditure. But the UK Government intended to restrict the uplift. Mobil, on behalf of the Beryl partners, argued that if it had been known that uplift was to be withdrawn the investment in Beryl B would not have been made.[6]

Export of oil from the field was by SPM buoys, the design details of the buoys was as follows.[2]

Beryl SPM loading buoys
SPM A (SPM1) SPM B (SPM2)
Coordinates 59.554322 1.562667 59.534403 1.559217
Type Articulated lattice tower Articulated cylindrical tower
Water depth, metres 119 120
Supply from 32-inch pipeline from Beryl A 32-inch pipeline from Beryl A
Capacity, barrels/h 40,000 40,000
Loading hose 16-inch 16-inch
Height, metres 149 166
Weight, tonnes 1,200 2,415
Fabrication CFEM ACMP, Marseille
Installation September 1975 September 1982

In 1985 SPM1 broke free from its moorings and was damaged beyond repair. A replacement, SPM3, was installed in 1987.[5]

An emergency flare is bridge-linked to Beryl A. This comprises a 600 feet (183 m) horizontal steel bridge. The bridge is supported by a 410 feet (125 m) high steel tower with a concrete gravity base.[2]

Production

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Beryl A was planned to have 30 production wells and 10 gas or water injection wells.[2]

The processing plant on Beryl A had a nominal capacity of 300,000 barrels of oil per day. There are two parallel process trains each capable of processing 150,000 bbl/day. Oil from the wellheads flows to one of the two High Pressure Separators operating at 150 psi where gas flashes off. Oil then passes to the Low Pressure Separator operating at 3 psi for further gas removal. From here oil flows to the storage tanks prior to export via the SPM buoys. Off-gas from the LP separators is compressed to 150 psi in a centrifugal compressor capable of compressing 12 MMSCFD. The compressed gas is mixed with off-gas from the HP Separator the combined flow of 150 MMSCFD is compressed in 2 stages to 5,200 psi and is injected into the reservoir. Gas injection started in November 1977.[2]

Deoxygenated seawater was injected into the reservoir at up to 100,000 barrels per day, this commenced in January 1979.[2]

Beryl B was planned to have 14 production wells, 5 water injection and 2 gas injection wells.

Processing plant comprised a single 3-phase Separator and an electric motor driven gas compressor.[2]

Redevelopment

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Further fields in the Beryl area were developed through Beryl A and B.[7]

From 1979 oil was produced from three subsea satellite wells. These were connected to Beryl A by 6-inch flowlines.[2]

Beryl subsea wells
Well 9/13a-6A 9/13a-15 9/13a-20B
Distance 3.35 km 7.01 km 4.57 km
Installation November 1978 January 1979 September 1979
First production End 1979 End 1979 End 1979

Further developments included production from small oil and gas fields in the Beryl area. Information on these fields is summarized in the table.[7] [8] [4] Nevis, Ness and Linnhe are named after Scottish lochs.

Beryl area satellite fields
Field Nevis South Nevis North, Central, West Ness Buckland Skene Linnhe
Block 9/13 9/13 9/13b 9/18 9/19 9/13
Discovery 1986 1999 2001 1988
Recoverable reserves, million tonnes 5.4
Oil gravity, °API 37
Water depth, metres 108 113 120 118 123
Production start 1996, now ceased 1988 1999 2001 1989, ceased 1991
Production rate 1.0 million tonnes/year 30,000 bbl/d 180 MMSCFD
Production to Beryl A Beryl B Beryl B Beryl A Beryl A Beryl B

Decommissioning

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Nevis South and Linnhe subsea installations have been decommissioned.[4] [7]

References

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  1. ^ a b Department of Trade and Industry (1994). The Energy Report. London: HMSO. pp. 32 and map 7. ISBN 0115153802.
  2. ^ a b c d e f g h i j k l m Oilfield Publications Limited (1985). The North Sea Platform Guide. Ledbury: Oilfield Publications Limited. pp. 51–68.
  3. ^ Knutson, C.A. and J.C. Munro (1991). "The Beryl Field, Block 9/13, UK North Sea". Geological Society London, Memoirs. 14: 33–42.
  4. ^ a b c "Beryl Field". Offshore Technology. Archived from the original on 2010-05-07. Retrieved 16 October 2021.
  5. ^ a b c "Charting 40 Years Of Production From The Beryl Field". issuu. 2016. Archived from the original on 2021-10-17. Retrieved 16 October 2021.
  6. ^ Kemp, Alex (2012). The official history of North Sea oil and gas. Abingdon: Routledge. p. 522. ISBN 9781138019034.
  7. ^ a b c A Barrel Full (2015). "Beryl Oil Field". a barrel full. Archived from the original on 2012-05-20. Retrieved 16 October 2021.
  8. ^ "OSPAR Inventory of Offshore Installations - 2017". ospar.org. 2017. Archived from the original on 2021-10-17. Retrieved 16 October 2021.