Optimizing Offshore Asset Management: Strain and Motion Monitoring for Steel Catenary Risers

Abstract In this paper, we will introduce 4Subsea’s strain and motion monitoring solution for steel catenary risers featuring a diver-installable subsea clamp. The clamp is a tool to measure structural loads to mitigate risk related to riser fatigue and flex joint degradation. The paper will detail one such strain and motion sensor clamp to be installed on FPSOs in Brazil. The monitoring solution deliver data required to provide critical insight, decision support and predictive maintenance. The autonomous sensors mounted in the clamp log strain and motion data continuously for up to 18 months, with battery and data storage capacity supporting operations at 10Hz. Alternatively, cabling to the topside allows for extended monitoring beyond 18 months. The use of sensors to monitor riser responses allows real data to be integrated with trained digital models giving operators insight into actual riser motions, loads and stresses. This reduces the complexity and cost of monitoring systems while improving their reliability. Clients have the flexibility to retrain the model after 12, 24 months, or longer, based on operational needs. This approach enables proactive asset management, reducing risks of costly repairs or production shutdowns. With this sensor technology, the riser monitoring clamp allows operators to minimize downtime, reduce operational costs, and maximize asset longevity. The strain and motion sensor clamp employs fully autonomous technology to monitor steel catenary risers (SCRs) on both new and existing assets, including aging infrastructure. This retrofittable clamp solution delivers direct strain measurements, and the sensor data is used to create a digital twin, providing valuable insights into riser behavior during extreme weather events and supporting the lifetime extension of SCRs.