Geothermal Digital Twins

Maximising nett energy output of a geothermal system is essential to make geothermal energysuccessful. A Digital Twin of the system is an effective tool to optimise the performance and to gaincontrol on well integrity risks.This paper presents a digital twin framework for geothermal systems, focusing on two keychallenges for long-term field and assets performance: injectivity and well integrity. Injectivitydecline, caused by reservoir changes, scaling, and operational conditions, reduces operationalefficiency, while incremental injectivity may occur due to factors like temperature effects.The injectivity monitoring application of the digital twin includes real-time calculation of the injectivityindex. Moreover, Hall and skin factor plots are presented to enables scenario analysis in addition tothe real-time monitoring. As a result, a decline in injectivity, due to scaling issues, is reflected in adecreasing injectivity index, an increased skin factor and a deviation of the Hall derivative from theHall plot showing a steeper positive slope.Well Integrity Management Systems (WIMS) are becoming mandatory for deep geothermal systemsseveral countries now. The digital twin can monitor the status of the WIMS compliance. A digital twinusing real-time data and corrosion rate models enables in-time decision making for an optimizedoperational scenario and scheduled maintenance preventing expensive repairs, unplanneddowntime or significant shortened well life and reputation damage. The WIMS Dashboard visualisesthe well integrity status using a real-time model to determine the corrosions rate. Corrosion ratepredictions are then used to optimize maintenance schedules, adjust the frequency of loggingactivities, and facilitate proactive interventions. These predictive models are validated throughphysical inspections using calliper logs and coupon samples, providing a feedback loop thatenhances model accuracy and are based on real-time data collection from operational parametersand corrosion probes, combined with semi-real-time data from fluid chemistry analysis.In addition to the architecture of the digital twin, a case study will be presented to demonstrate theeffectiveness of the injectivity and corrosion applications. The developed digital twin framework isbeing tested on and integrated into a geothermal plant in the Netherlands for direct-use heatingapplication.