Safe and reliable access to offshore energy, whether it be through hydrocarbon or renewable sources, requires offshore infrastructure held on station by well designed, well installed and well monitored mooring systems. The bounds of what is possible with mooring integrity monitoring technology has expanded in recent years, providing stakeholders with a more complete view of risk over the life of the floating facility. As regulatory requirements eventually follow from these innovations, there is also increasing pressure on operators to expand their monitoring capabilities to retain compliance.
This paper presents an overview of some of the insights gained from using Global Navigation Satellite System (GNSS) vessel position data and metocean data for real-time mooring integrity monitoring. The means through which a GNSS-based integrity monitoring system can be programmed to detect mooring failures is presented and compared with alternative monitoring techniques. The potential for such a GNSS-based system to complement or replace other methods such as in-line load cell is discussed, particularly in scenarios where the installation or replacement of such direct mooring line monitoring technologies can be prohibitive from an operational or cost perspective.
The practical considerations gathered from seven combined years of operational mooring integrity on various offshore facilities are also discussed, including the use of metocean monitoring and forecasts, data rate, resolution, accuracy, delay and quality considerations, and the challenges involved in rolling out such a system on an operating facility.
This paper provides operators of floating facilities with insights into the kind of data which should be considered for an effective monitoring solution, as well as an approach to combine different data streams (vessel offsets, first order motions and environmental data) to derive a holistic assessment of mooring integrity. This information can be valuable for operators defining the scope of monitoring for new facilities or looking to get the most value out of the data on their existing facilities, where a system such as the one presented can provide a quantitative basis for operational decisions and improve the regulatory and risk compliance of offshore facilities.