Vilje

Location and Geography

• The Vilje oil field is located in the central part of the North Sea, approximately 20 kilometres northeast of the Alvheim field.
• The water depth at the site is 120 metres.

Operator and Partners

• The original operator was Marathon Oil Norge AS, but in 2012, the operatorship was transferred to Marathon from Statoil.
• The partners in the project include:
  • Marathon Oil Norge AS (46.90% interest)
  • Statoil Petroleum AS (28.85% interest)
  • Total E&P Norge AS (24.24% interest). However, in 2014, PGNiG acquired Total's stake.

Field Development

• The field was discovered in 2003, and the Plan for Development and Operation (PDO) was approved in 2005.
• The field development concept includes three horizontal subsea wells tied back to the Alvheim production, storage, and offloading vessel (FPSO).
• Initially, the development concept mentioned two subsea templates and two production wells, but it was later clarified that there are three horizontal subsea wells.

Production

• Production from the Vilje field started in 2008.
• The field was expected to produce 21,000 barrels of oil per day in 2012.
• The well stream is routed by pipeline to the Alvheim FPSO, where the oil is offloaded to shuttle tankers. The gas is transported by pipeline from Alvheim to the Scottish Area Gas Evacuation (SAGE) pipeline in the UK sector.

Geology

• The reservoir is a turbidite deposit in the Heimdal Formation of the Paleocene age.
• The reservoir lies approximately 2,150 metres below sea level and is part of a fan system with good quality sandstone.

Recovery Strategy

• The field is produced using natural water drive from the regional underlying Heimdal aquifer.

Current Status

• Production from the field is steadily declining due to increasing water cut, although the recoverable volume estimates are significantly higher than initially predicted in the PDO.
• In 2014, Marathon Oil announced the sale of its Norway business, including the Vilje field, to Det Norske. Subsequently, PGNiG acquired Total's stake in the field.

Contractors and Infrastructure

• Technip was awarded an engineering, procurement, installation, and commissioning (EPIC) contract for the subsea umbilicals, risers, and flowlines, as well as manifold installation and subsea equipment protection work.
• KWsubsea was involved in the installation of offshore pipelines.

Future Context

• While the Vilje field itself is not the focus of current expansion projects, the broader Alvheim area is undergoing life extension and expansion efforts by Aker BP, which includes upgrading the Alvheim FPSO and developing nearby fields.