Digital Twin Enhanced Fiber-Optic Sensing System for Wellbore Structural Health Monitoring

Geothermal energy offers significant energy generation capacity to support America’s transition from fossil fuels to renewables. Enhanced Geothermal Systems (EGS) allows extraction of harder-to-reach geothermal energy by actively pumping cold fluids into hot basement rock. DOE and industry seek to improve geothermal well completion, stimulation, and/or operations via improved understanding and prevention of wellbore impairment. IFOS proposes an innovative, photonic-computation-based wellbore integrity and SHM system, WellSense™, for real-time wellbore health monitoring and prognostics. The system will leverage an integrated distributed fiber optic sensing system that integrates multifunctional and multiplexable Fiber Bragg Grating (FBG) sensors with Distributed Temperature Sensing (DTS) for high-precision strain, pressure, and temperature measurements. The multifunctional WellSense™ system will relate multi-parameter, multi-point direct measurements made with fiber-optic sensors to wellbore conditions in real-time. The fiber optic cable will be suitably ruggedized for installation in high temperature and pressure environments, thereby rendering it capable to operate in harsh regimes (up to 200°C and 5,000 PSI). In addition to IFOS’ on-the-fly, light-speed optical computation performed in the fiber sensing layer, the on-board analytics will leverage a ‘Digital Twin’ system that integrates geophysical, mechanical, and chemical models of the test specimen with numerical modeling and AI- enhanced edge computing. The ‘Digital Twin’ framework will integrate virtual representations of wellbore components and surface production systems behavior with models of reservoir flow to map calculated temperature, pressure, acoustic waveforms, and energy flow parameters to specific impairment and failure signatures and mechanisms. This will allow the on-board diagnostics and prognostics architecture to optimize the trade-off between failure probability and production to manage remedial actions. In Phase I the IFOS multidisciplinary team will demonstrate the feasibility of its fracture characterization system. In Phase II, the team will perform field validation of an integrated engineering prototype. The borewell characterization provided by IFOS’ photonic system will increase the energy efficiency of EGS production by giving operators greater understanding of the structural health of the well.