A DIGITAL TWIN TO ESTIMATE THE REMAINING FATIGUE LIFE OF RISERS

Digital Twins can be defined as virtual models of physical systems, used to create simulations to predict the performance of equipment or processes. In offshore production systems, Digital Twins have been employed to increase operational efficiency and enhance safety. They can provide real time data to support structural integrity management decisions, such as life extension of submarine structures. The objective of this work is to present a Digital Twin application aiming to predict the remaining fatigue life of risers connected to floating production units, focusing on the top region and on tensile armors. This tool captures real-time monitored internal pressures and movement data from sensors installed on the vessels and automatically calculates the fatigue damages and remaining lives. The Riser Fatigue Digital Twin employs hybrid methods to perform global and local analyses quickly, and then calculates damage for each sea state to which the production unit and the risers are subjected. The consideration of actual measured motions at the platforms reduces uncertainties associated to traditional fatigue life evaluation methods that typically rely on vessel motions derived from Response Amplitude Operators (RAOs) and wave spectra. The presented case study illustrates the fatigue life calculation for two risers employing the proposed approach. The obtained results are compared to results referent to a simplified and traditional design method. It is expected that the Digital Twin will be very useful in providing real-time information regarding the structural integrity of the risers in operation, reducing the overall time spent on such analyses, and facilitating data-driven decision-making for integrity managers.