The Offshore Asset Lifecycle
The stages an offshore asset passes through, and how decisions made early limit what operations can do later.
11 min
Activities: 0 of 2
Operations inherit the design
An offshore installation may produce for twenty or thirty years or more. The people who operate it rarely chose its design. They inherit decisions made years earlier about layout, equipment, access, bed space and how many people the installation needs. Understanding the lifecycle helps an operations team see which problems they can fix and which they must manage for the life of the asset.
Lifecycle of an offshore asset
- 1
Concept
Concept selection
The development concept is chosen: fixed platform, floating facility or subsea tie-back. This sets most of the cost and much of the operating philosophy.
- 2
Design
Front-end and detailed design
Layout, equipment selection, safety systems, manning philosophy and maintenance access are fixed. Operations input here is cheap; later it is very expensive.
- 3
Build
Fabrication, installation and hook-up
Modules are built in yards, transported, installed and connected offshore.
- 4
Start-up
Commissioning and start-up
Systems are tested and handed over from the project team to operations, system by system, with punch lists of outstanding items.
- 5
Operate
Production and late life
Plateau, decline, rising water, ageing equipment and, often, life extension beyond the original design life.
- 6
Remove
Decommissioning
Wells plugged and abandoned, facilities cleaned, removed and recycled or disposed of.
Two examples of design shaping operations
Example 1: valve access. On one platform, designers placed several manual isolation valves high in a congested module with no permanent platform. Every isolation needs scaffolding, which adds days to maintenance jobs and creates work at height. The operations team cannot move the valves easily, so they plan scaffold in advance and push for permanent access during the next shutdown.
Example 2: bed space. A floating facility was designed for a small crew because the field was expected to be simple. Ten years later, water handling problems need more maintenance, but there are not enough beds. Every campaign competes for space, and the team must use walk-to-work vessels to bring extra people.
Late life and life extension
Put the lifecycle stages in order
- 1Front-end and detailed design
- 2Fabrication, installation and hook-up
- 3Commissioning and handover to operations
- 4Decommissioning
- 5Concept selection
- 6Production and late life
Handover before first oil