Statoil and its partners have submitted an amendment to the Plan for Development and Operations (PDO) for the Gullfaks license to the Ministry of Petroleum and Energy for Phase 1 of the Shetland/Lista development.
Phase 1 of the development is expected to add 18 million barrels of oil equivalent, and will help increase the resilience of the area for continued operation of the Gullfaks platforms in the North Sea. The development concept is based on reuse of existing wells (a total of 15) from the Gullfaks platforms, and will not require any new infrastructure.
The Shetland Group/Lista Formation has been producing under a test production license since 2013. The submitted plan defines the more long-term development of these resources. This, however, is only the first phase of the development, which involves depressurization down to bubble point pressure in the reservoir.
The Shetland Group and Lista Formation have different properties compared with the deeper deposits of the Brent Group, where the main Gullfaks reservoirs are located. The producing interval in Shetland/Lista consists of thin limestone beds that are fractured and thus contribute to productivity. Shetland/Lisa productivity was initially established in December 2012 and has been confirmed through perforation in another three existing Gullfaks wells. This has warranted commercial development of the play.
The current recovery rate on the main Gullfaks field is 59%, and, with a productive life toward 2036, Statoil and its partners aim to further increase this rate. Shetland/Lista will add new valuable barrels. Investment costs are estimated at some NOK 900 million. Statoil continues its efforts to realize the next phase based on pressure maintenance. This is expected to improve the recovery rate for Shetland/Lista.