Gudrun

Location and Geology

• The Gudrun oil and gas field is located in the central part of the North Sea, approximately 50-55 kilometers north of the Sleipner Øst field, within production licence 025 (PL 025) or block 15/3P.
• The field is situated at a water depth of about 109-110 meters (358-361 feet).
• The reservoirs are of the Jurassic era, specifically containing oil in the Upper Jurassic Draupne Formation and gas in the Middle Jurassic Hugin Formation. These reservoirs are at depths ranging from 4,000 to 4,760 meters.

Discovery and Development

• The Gudrun field was discovered in 1975.
• The plan for development and operation (PDO) was approved by the Norwegian Government in June 2010, after being submitted in February 2010.
• The development involved a significant investment of $2 billion.

Platform and Infrastructure

• The field is developed using a traditional steel platform resting on the seabed, supported by a 7,400-ton steel jacket. The platform has 16 well slots, with seven production wells initially drilled.
• The platform is equipped with facilities for partial processing of the oil and gas produced from the field. It also includes living quarters and facilities to handle production from the Sigrun subsea satellite development.
• The platform is tied back to the existing facilities at the Statoil-operated Sleipner field via two pipelines, one for oil and one for wet gas. The gas is further processed at the Sleipner T platform, and the oil is sent to the Kårstø processing plant for final treatment.

Production

• First production from the Gudrun field began on April 7, 2014. The platform was officially inaugurated in August 2014.
• The field produces both oil and gas, with estimated reserves of approximately 184 million barrels of oil equivalent. This includes about 70 million barrels of oil and 1.7 trillion cubic feet of gas.
• Production is mainly achieved through pressure depletion, with part of the reservoir in the Draupne Formation also produced using water injection, which started in 2022.

Processing and Transport

• The oil and gas produced are partially processed on the platform before being transported to the Sleipner A facility for further processing. The gas is then sent to the Sleipner T platform for carbon dioxide removal and subsequently exported to Europe through the Gassled system. The oil is stabilized at Sleipner A and then sent to the Kårstø processing plant for final treatment before shipping.

Operators and Partners

• The field is operated by Equinor (formerly StatoilHydro), which holds a 46.8% stake. Other partners include OMV (24%), and Eni (previously GDF SUEZ E&P Norge) with a 25% stake, although the exact current ownership percentages may have changed slightly.

Contractors and Contracts

• Key contractors involved in the development include Aker Solutions, which constructed the jacket and carried out modifications to the existing facilities in the Sleipner area; Aibel, which engineered and constructed the topside facilities; Saipem, responsible for the transport and installation of the platform jacket and topside facilities; and Halliburton, which provided directional drilling, logging-while-drilling, cementing, drilling fluids, and completion equipment and services.

Production Status and Future

• As of the latest updates, production from the Gudrun field has started to decline. Water injection in parts of the Draupne reservoir began in 2022, and a second drilling campaign was completed in 2022. Infill targets for the third drilling campaign are being matured, and a new 4D seismic survey was completed in 2023. The field is expected to continue production until it reaches its economic limit in 2037.

High-Pressure/High-Temperature (HP/HT) Field

• The Gudrun field is classified as a high-pressure/high-temperature (HP/HT) field, requiring special technology for its development and operation. The reservoir pressure is approximately 820 bar.