Session: 01-08-02 Digitalization, AI/ML, Digital Twins - II

Submission Number: 156248

The Mooring Digital Twin: Fatigue and Integrity Monitoring to Support Life
Extension 

Operators of floating production facilities must demonstrate their mooring systems are fit for service throughout operational life. When seeking life extension, the mooring system must be reassessed considering its present condition, load history, and forecast degradation. Given the significant CAPEX of mooring replacements or repairs, accurate assessment of fatigue loading and resistance, including the influence of degradation mechanisms such as corrosion and wear, is often crucial for the viability of extending the operating life of the facility using the existing moorings.

This paper presents the application of a mooring digital twin to leverage operational data for both justifying mooring system life extension and implementing continuous integrity monitoring, in the absence of direct mooring line monitoring. The resulting system addresses Classification Society requirements while providing assurance on long-term system integrity.

The digital twin approach combines detailed numerical analysis with vessel position and motion data, environmental measurements, and operational records such as vessel loading data and inspection data to create a virtual representation of the mooring system’s fatigue utilization. This enables a more accurate prediction of fatigue load duty compared to design simulations, while accounting for various degradation mechanisms, creating a framework for continuous fatigue monitoring. A parallel application of mooring integrity monitoring, using the vessel position data to infer the integrity of the mooring lines was also deployed on the same digital twin platform. 

Applied to OMV’s FPSO in New Zealand, the mooring digital twin enabled life extension through the implementation of live monitoring of fatigue duty and potential mooring failures. Notably, this approach satisfied Classification Society requirements for reduced fatigue safety factors using reliable operational data. This approach provides operators a pathway to justify life extension while giving Classification Societies, regulatory agencies and insurers greater confidence in ongoing system integrity. 

Presenting Author: Kanishka Jayasinghe AMOG

Presenting Author Biography: Kanishka Jayasinghe is a Principal Engineer and the Digital Team Lead at AMOG Pty Ltd, a specialist consultancy founded in 1991 which is active in the offshore oil and gas, marine, mining and defence sectors. With a strong background in hydrodynamics, structural mechanics, instrumentation and analytics, Kanishka is AMOG’s lead in helping our clients realise the potential of increased digitisation and Industry 4.0.

Since joining AMOG in 2012, Kanishka has primarily worked for clients in asset-heavy, high criticality operations in the offshore energy and mining industries, on a diverse array of technically challenging problems. Kanishka has supported offshore energy projects throughout their life cycle, from feasibility assessments to front end engineering and design (FEED), detailed design, installation engineering, operational support and decommissioning. His analytical skills cover a broad range of dynamic systems, particularly in offshore environments. These include the assessment of moorings, risers, subsea pipelines, offshore heavy lifts, and fixed and floating offshore structures. He has extensive experience in asset integrity management, particularly for subsea assets, having performed criticality assessments and life extension assessments, written inspection specifications and attended offshore as a supporting engineer for refurbishment and inspection campaigns.

Kanishka has a strong background in the evaluation of monitoring data from dynamic structures and process equipment to feed back into operational decisions and perform forensic engineering analysis. Kanishka has also designed and deployed instrumentation in harsh, remote environments to characterise the dynamic response of machines and structures.

Kanishka has also extensively supported AMOG's efforts in Joint Industry Projects, specifically regarding the corrosion of offshore mooring chain (through both the SCORCH JIP and the DeepStar CTR on Microbiologically Influenced Corrosion of Chain) and is closely involved in several prospective JIP's including Chain Wear JIP and Squall Moorings JIP.