Per Hokstad, Solfrid Håbrekke, Roy Johnsen (NTNU) and Sigbjørn Sangesland (NTNU)
2010-03-19
176 sider + 75 sider (vedleggsrapport)
Pris ved bestilling av papirutgave: NOK 350,- (hovedrapport), NOK 250,- (vedleggsrapport)

Life extension (LE) is an important issue for a number of facilities on the Norwegian Continental Shelf. Many fields have recoverable oil/gas reserves extending the facility’s original design life, but certain analyses are required to ensure that safety will not be compromised in case of LE.

The report provides an overview of issues related to ageing and management of LE for offshore facilities. The principal aspects of an LE assessment process is outlined, including physical degradation, obsolescence and human/organisational consequences. This work comprises data collection, identification of relevant requirements and regulations, and analyses. A screening process is also needed to identify the systems, structure and components (SSC) where a more detailed analysis is required. Further, the report presents an overall approach for risk assessment related to LE and provides relevant measures for the LE period. The LE management plan is discussed, too.

Five systems are studied in more detail to illustrate typical ageing phenomena and possible challenges:
1. Material handling and lifting equipment.
2. Wells.
3. Pipelines, risers and subsea systems.
4. Topside processing equipment.
5. Safety systems.

2-5 are investigated mainly with respect to physical degradation, and 1 (and slightly 2) are investigated mainly with respect to obsolescence (outdated operations/technology) and organisational challenges.

Note that structures are not dealt with specifically in the report, as much has been written on ageing and structures.