Schwedeneck-See oil field explained

Schwedeneck-See oil field
Country:Germany
Region:Baltic Sea
Offonshore:Offshore
Location:Bay of Kiel
Operator:Deutsche Texaco; RWE-DEA
Discovery:July 1978
Start Production:November 1984
Abandonment:2000
Oil Production Bbl/D:8000
Recover Oil Bbl:18.5
Formations:Jurassic sandstone
Api:27.6
Contractors:C.G. Doris and IMS

The Schwedeneck-See oil field was a significant oil field in the German sector of the Baltic Sea. It was the first oil field in the Baltic, and was Germany’s first offshore oil field. lt produced oil from 1984 until 2000.

The field

The Schredeneck-See field is located in Kiel Bay in the Baltic Sea about 5 km east from the coast.[1] The reservoir is a Jurassic sandstone at a depth of about 1,511 metres, with a thickness of 8.2 m. The properties of the reservoir and its fluids are: [2]

Schredeneck-See oil field!Property!Value
Reservoir pressure130 bar
Reservoir temperature55°C
Permeability400-2000 md
Specific gravity0.875 kg/l
Gas Oil Ratio51 scf/stbbl
Paraffin content9 %
Viscosity13 mPas
Pour point16°C
API gravity27.6°
Porosity26 %
Water saturation 25 %
Sulfur content1.3 %
The field was discovered in July 1978 and had recoverable reserves of 2.5 million tonnes or 18.5 million barrels of oil. [3]

Development

The field was developed by a 50/50% joint venture with Deutsche Texaco AG and Wintershall AG. The project was estimated to cost in excess of DM 300 million (1983 prices). It was developed using two offshore installations and a shore base. There were plans to construct one or two further offshore installations to further develop the field but these were not constructed.[4] The operator opted to build two, single column, concrete gravity base structures to withstand seasonal ice floes in the Baltic.

The platforms were designed by C. G. Doris and IMS of Hamburg. The gravity base comprises a central shaft 13 m in diameter surrounded by 8 shafts of the same diameter and a height of 12.85 m to protect the central column and for water ballasting. The base area was 38 by 38 m.The height of the column was 36.95 m and supported the lower deck of the topsides at this level.

Schredeneck-See oil platforms!Installation!Coordinates!Water depth !Weight!Type!Legs!Well slots!Producing  wells!Installed!Production start!Production to
Platform AR 35 70 716 H 60 51 27025 m16,500 tonnesConcrete gravity base1127August October 1983November 1984Waabs shore terminal by 5.5 km 10-inch pipeline
Platform BR 35 63 475 H 60 48 40716 m13,200 tonnesConcrete gravity base1129August October 1983Summer 1985Waabs shore terminal by 3.5 km 10-inch pipeline

Crude oil was processed through a closed system with processing onshore at Waabs, oil was then sent to the Texaco refinery at Heide. Associated gas produced at Waabs was used for space heating at the terminal and at the nearby Damp 2000 recreation centre. Because of the low gas-oil-ratio there was no flaring of gas on the platforms. Electrical submersible pumps were installed within the wells at a depth of about 1,200 m. The installations were operated remotely from the shore station. When initially commissioned the field produced 1,100 tonnes/d or 8,000 barrels/day of crude oil.

Decommissioning

The RWE-DEA corporation closed the installations in 2000. The topsides were removed and the gravity bases refloated and removed for disposal in 2002.[5]

See also

Notes and References

  1. Book: Oilfield Publications Limited. The North Sea Platform Guide. Oilfield Publications Limited. 1985. Ledbury UK. 603–7.
  2. Book: Klatt, H.J and H.C. Klumker; K.A. Siebel. All Days . Design and Operation of Two Remote Controlled Platforms in the Baltic Sea, West Germany . 1988. https://doi.org/10.2118/17624-MS. International Meeting on Petroleum Engineering, Tianjin, China, November 1988.. 10.2118/17624-MS. https://onepetro.org/SPEIOGCEC/proceedings-abstract/88IMPE/All-88IMPE/SPE-17624-MS/68565.
  3. 1984. Schwedeneck-See: the first German offshore oilfield. Oil Gas European Magazine 1. 10. 2. 56–8.
  4. Web site: Putsch. G. Developments of German offshore oil and gas production.
  5. Web site: Overdick. 2002. Schwedeneck See - Gravity base platform.