The Statfjord field was discovered by Mobil in 1974 and Statoil assumed operatorship on 1 January 1987. Since 1979 Statfjord A has produced some 1.5 billion barrels of oil and 29 billion cubic metres of gas, adding value worth NOK 475 billion.

Production until 2020
After more than three decades’ production the Statfjord field has now entered late-phase production.  Statoil established the Statfjord A decommissioning project in 2010. This is the first major closure of an installation on the Statfjord field.

The original plan was to complete the decommissioning in 2017, but partners Statoil, Centrica and ExxonMobil have now decided to extend production from the platform until 2020.

According to the Petroleum Act, licence holders have to submit their plan for disposal to the Ministry of Petroleum and Energy five years at the earliest, and two years at the latest, before an installation is decommissioned.
 
The decommissioning project consists of many demanding elements, including the permanent plugging of 40 wells. Parallel with the planning and implementation of permanent plugging, new wells are also being drilled. 

 “The field can still offer valuable resources. So the value of Statfjord A will increase, even in the decommissioning phase,” says Thor Viggo Aarrestad, Statoil’s manager for the Statfjord A decommissioning project.

Many preparations
The project is now fully engaged in preparing impact studies and plans in connection with decommissioning. One of the many challenges to address is how to prepare the installation for dismantling.

Among other things, the project is considering the sequence in which the systems are to be shut down, the possibility of using the living quarters in the first phase of removal, and how to ensure that the platform is kept free of hydrocarbons during the dismantling operations.