Sleipner Øst

Sleipner Øst Field Profile

Location and Geography

The Sleipner Øst Field is located offshore Norway in the central part of the North Sea, specifically in blocks 15/6, 15/8, and 15/9. The field lies at a water depth of 80 meters.

Discovery and Development

• The Sleipner Øst Field was discovered in 1981.
• The Plan for Operation and Development (PDO) was approved in 1986.
• Production began in August 1993.

Field Characteristics

• The Sleipner Øst Field is a gas and condensate field.
• The original recoverable reserves were 122 million standard cubic meters (Sm³) of oil equivalent of gas and condensate. As of the current data, the field has remaining reserves of 0.3 million Sm³ of oil equivalent of gas and condensate.

Reservoir Details

• The reservoirs of the Sleipner Øst and associated Loke fields are located in the Paleocene turbidite sandstone of the Ty Formation, Middle Jurassic shallow marine sandstone of the Hugin Formation, and continental sandstone of the Triassic Skagerrak Formation. Additionally, gas has been found in the Heimdal Formation.
• The Ty Formation has good reservoir quality, while the Skagerrak Formation generally has poorer reservoir quality compared to the Ty and Hugin Formations.
• The reservoirs are at a depth of approximately 2,300 meters.

Production and Recovery Strategy

• The field is currently in the late tail production phase.
• The Hugin Formation reservoir is produced by pressure depletion, while the Ty Formation reservoir was produced by dry gas recycling until 2005. Production from the Ty reservoir stopped in 2012.
• To optimize production, wells are produced at reduced inlet pressure.
• The main focus now is on increasing reserves and decreasing production decline. It is expected that Sleipner Øst will continue to operate for tied-back fields after its own production ceases.

Infrastructure and Platforms

• The field is developed with the Sleipner A platform, an integrated processing, drilling, and accommodation facility with a concrete base structure.
• The Sleipner R riser facility connects Sleipner A to the pipelines for gas transport.
• The Sleipner T facility is used for processing and CO₂ removal.
• Two subsea templates were installed: one for production from the northern part of Sleipner Øst and one for production from the Loke deposit. The Alpha Nord segment was developed in 2004 with a subsea template connected to Sleipner T.

Tie-in Fields

• The field processes hydrocarbons from several tie-in fields, including Sigyn, Volve, Gudrun, and Gina Krog. The Utgard field is also tied back to Sleipner T for processing and CO₂ removal.

Transport and Export

• Sales gas is exported from the Sleipner A facility via the Gassled transport system (Statpipe, Zeepipe, and Europipe II) to markets in Emden and Zeebrugge.
• Unstable condensate is transported via pipeline to the Kårstø terminal in Rogaland for further processing and is then exported by ship.

CO₂ Storage

• The Sleipner area, including Sleipner Øst, is involved in a significant CO₂ storage project. CO₂ separated from produced natural gas is injected into the Utsira Formation, a shallow saline aquifer, to prevent atmospheric emissions. This is part of the Saline Aquifer CO₂ Storage (SACS) project.

Electrification

• In June 2020, Equinor and its partners decided to partially electrify the Sleipner Area, including the associated fields. The power from the shore is expected to start in 2024, with an estimated cost of around NOK 850 million ($81.49 million). A contribution of up to NOK 430 million ($41.22 million) from the Business Sector’s NOx Fund will be used for this electrification project.

Current Status

• The field is in the late tail production phase, with a focus on optimizing production and extending the field's life.
• The Sleipner Life Cycle Simulation Project, set to commence in the first quarter of 2024 and complete by the end of 2025, aims to model the processes of the platforms and facilities in the Sleipner Area to optimize operations.