EKOFISK

Discovery year
1969
Wellbore
Status
Producing
Licence

Operator:

ConocoPhillips Skandinavia AS

Area:

North sea

Production start:

15.06.1971

Historical investments per 31.12.2017:

144 159 MILL NOK (nominal)

Future investments from 2018:

40 296 MILL NOK (real 2018 NOK)

PRODUCTION FROM THE FIELD

Source: The Norwegian Petroleum Directorate

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PRODUCTION FROM THE FIELD

Development

Ekofisk is a field located in the southern part of the Norwegian sector in the North Sea. The water depth in the area is 70-75 metres. Ekofisk was discovered in 1969, and the initial plan for development and operation (PDO) was approved in 1972. Test production was initiated in 1971 and ordinary production started in 1972. Production was initially routed to tankships until a concrete storage tank was installed in 1973. Since then, the field has been further developed with many facilities, including facilities for associated fields and export pipelines. Several of the initial facilities have already been removed or are awaiting decommissioning. The initial field development started with three production platforms: Ekofisk A, Ekofisk B and Ekofisk C. Wellhead platform Ekofisk X and process platform Ekofisk J were installed in 1996 and 1998, respectively, as part of the Ekofisk II project. In 2005, wellhead platform Ekofisk M was installed as part of the Ekofisk Growth Project. A plan for water injection at Ekofisk was approved in 1983. Ekofisk K, which is the main injection facility, started water injection in 1987 and is still in operation. There had also been water injection at Ekofisk W from 1989 until 2009, when Ekofisk W was shut down and replaced by a subsea template, Ekofisk VA. A PDO for the development of Ekofisk South was approved in 2011. The project included two new installations in the southern part of the field: production platform Ekofisk Z and a subsea template for water injection, Ekofisk VB. Injection from Ekofisk VB and production from Ekofisk Z started in 2013. The accommodation facilities Ekofisk H and Ekofisk Q were replaced by Ekofisk L in 2014. In 2017, the authorities approved an amended PDO for an additional water injection template, Ekofisk VC.

Reservoir

Ekofisk produces oil from naturally fractured chalk of Late Cretaceous age in the Tor Formation and early Paleocene age in the Ekofisk Formation. The reservoir rock has high porosity, but low permeability. The reservoir has an oil column of more than 300 metres and lies at 3,000 metres depth.

Recovery

Ekofisk was originally produced by pressure depletion and had an expected recovery factor of 17 per cent. Since then, comprehensive water injection has contributed to a substantial increase in oil recovery. Large-scale water injection started in 1987, and in subsequent years, the area for water injection has been extended in several phases. Experience has proven that water displaces the oil much more effectively than anticipated, and the expected final recovery factor for Ekofisk is now estimated to be over 50 per cent. In addition to the water injection, compaction of the soft chalk provides extra force to drainage of the field. The reservoir compaction has resulted in about 10 metres subsidence of the seabed, especially in the central part of the field. It is expected that the subsidence will continue, but at a much lower rate.

Transport

Oil and gas are routed to export pipelines via the processing facility at Ekofisk J. Gas from the Ekofisk area is transported via the Norpipe gas pipeline to Emden in Germany, while the oil is sent via the Norpipe oil pipeline to Teesside in the UK.

Status

Production from Ekofisk is maintained at a high level through continuous water injection and drilling of new production and injection wells. The Ekofisk Life of Field Seismic (LoFS), installed in 2010, provides data for waterflood monitoring and reservoir management as well as observation of dynamic changes in the overburden. Drilling of wells, including remaining wells in the Ekofisk South development project, is ongoing. Water injection started from the subsea template Ekofisk VC in 2018.

ACCRUED INVESTMENTS IN NOMINAL NOK

Source: The Norwegian Petroleum Directorate

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ACCRUED INVESTMENTS IN NOMINAL NOK

NPD's CURRENT RESOURCE ESTIMATES

All numbers in mill. Sm3 o.e.

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NPD's CURRENT RESOURCE ESTIMATES – All numbers in mill. Sm3 o.e.
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OWNERS

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OWNERS

DISCOVERIES INCLUDED IN THE FIELD

DISCOVERY
2/4-2 Ekofisk

MORE INFORMATION

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