Floating Production Systems (FPS) remain on station many years without dry docking. The mooring lines, which ensure station keeping, are designed to last the entire service life of the FPS. However, many mooring line failures or premature replacements have occurred in the past. Within the LifeLine Joint Industry Project, supported by 15 companies, a new methodology to assess the mooring integrity of FPSOs by means of position measurements only has been developed. The methodology, which contains an event-based approach and a status-based approach, has been implemented in a software for on-board use. The software provides the operator real-time feedback regarding the status of the mooring lines.
The LifeLine JIP was initiated in 2018 and finalized in 2020. During this project a fully automated onboard software has been developed to assess the mooring integrity of spread moored and turret moored FPSOs. This software uses DGPS position measurements as input only. One of the biggest advantages of using position measurements for mooring integrity is that no subsea equipment is required making it in itself more reliable and easily maintainable. Another advantage is that a dry monitoring system allows to install the application on both new-built and existing units in the fields. In-service measurements and blind test simulations from 10 FPSOs with a wide variety of mooring systems and located in the worldwide oil and gas regions were used to validate the software.
The main goal of the LifeLine User Group is to support the practical application of the LifeLine technology on the field and to support further development needs. The scope of work comprises:
- Dedicated support for onboard installation
- Software maintenance and general support
- Lifeline for low displacement floaters (semisubmersibles, calm buoys)
The two years project started in July 2021 with user group and progress meetings during the FPSO JIP Weeks in Spring and Autumn 2021.