@conference {herrmann2026SEGWSudt,
	title = {Uncertainty-aware Digital Twins for Monitoring and Optimizing of Geological Carbon Storage},
	booktitle = {Net-Zero Emissions: Critical Minerals, Hydrogen, Nuclear, Geothermal, Wind, CCUS, and AI, SEG Workshop},
	year = {2026},
	month = {3},
	abstract = {Geological Carbon Storage (GCS) is the only truly scalable pathway to net-negative emissions on the path to net-zero, yet ensuring safe, cost-efficient, and verifiable GCS demands far more than static reservoir models. We introduce an uncertainty-aware Digital Twin framework that delivers continuous, probabilistic monitoring of subsurface CO$_{2}$ plume dynamics and enables risk-informed operational decisions in real time. At the core of our approach is a machine-learning-enabled data assimilation framework where Simulation-Based Inference (SBI) replaces linear ensemble Kalman filtering, enabling the framework to handle highly nonlinear CO$_{2}$ dynamics and seismic observations. This allows the Digital Twin to characterize the full posterior distribution of reservoir states{\textemdash}fluid saturations and pressures{\textemdash}conditioned on multimodal time-lapse observations from imaged surface seismic data and well measurements. The framework operates recursively: neural networks are trained offline on ensembles of simulated reservoir states and simulated observations, capturing complex nonlinear subsurface dynamics and observations. Once trained, the Digital Twin assimilates incoming field data in near real-time, continuously updating the probabilistic reservoir model as new measurements arrive. By maintaining a probabilistic rather than deterministic view of reservoir state, our Digital Twin enables decision-making under uncertainty{\textemdash}optimizing CO$_{2}$ injection schedules while managing the risk of exceeding critical fracture pressures, and identifying monitoring strategies that maximally reduce uncertainty. Validated on realistic numerical simulations of GCS scenarios, this framework offers a concrete path toward safer, more transparent, and verifiable Geological Carbon Storage operations.},
	keywords = {Amortized Variational Inference, Bayesian inference, CIG, conditional normalizing flows, data assimilation, deep learning, digital twin, experimental design, GCS, Imaging, Inverse problems, permeability, reservoir simulation, rock physics, RTM, SEG, SLIM, Summary Statistics, Uncertainty quantification},
	url = {https://slim.gatech.edu/Publications/Public/Conferences/SEG/2026/herrmann2026SEGWSudt},
	author = {Abhinav Prakash Gahlot and Haoyun Li and Felix J. Herrmann}
}
@conference {herrmann2026HALuad,
	title = {Uncertainty-aware Digital Twins for Monitoring and Optimizing of Underground Energy Operations},
	booktitle = {Landmark Innovation Forum \& Expo 2026, LIFE2026, Orlando, FL},
	year = {2026},
	month = {4},
	keywords = {Amortized Variational Inference, Bayesian inference, CIG, conditional normalizing flows, data assimilation, deep learning, digital twin, experimental design, GCS, Imaging, Inverse problems, permeability, reservoir simulation, rock physics, RTM, SLIM, Summary Statistics, Uncertainty quantification},
	url = {https://slim.gatech.edu/Publications/Public/Conferences/Halliburton/2026/herrmann2026HALuad},
	author = {Abhinav Prakash Gahlot and Haoyun Li and Felix J. Herrmann}
}
@article {gahlot2024uads,
	title = {An uncertainty-aware Digital Shadow for underground multimodal CO2 storage monitoring},
	journal = {Geophysical Journal International},
	year = {2025},
	note = {(Geophysical Journal International)},
	month = {5},
	abstract = {As a society, we are faced with important challenges to combat climate change. Geological Carbon Storage (GCS), during which gigatonnes of super-critical CO2 are stored underground, is arguably the only scalable net-negative CO2-emission technology that is available. While promising, subsurface complexities and heterogeneity of reservoir properties demand a systematic approach to quantify uncertainty when optimizing production and mitigating storage risks, which include assurances of Containment and Conformance of injected supercritical CO2. As a first step towards the design and implementation of a Digital Twin for monitoring and control of underground storage operations, a machine-learning-based data-assimilation framework is introduced and validated on carefully designed realistic numerical simulations. Because our implementation is based on Bayesian inference, but does not yet support control and decision-making, we coin our approach an uncertainty-aware Digital Shadow. To characterize the posterior distribution for the state of CO2 plumes (its CO2 concentration and pressure), conditioned on multi-modal time-lapse data, the envisioned Shadow combines techniques from Simulation-Based Inference (SBI) and Ensemble Bayesian Filtering to establish probabilistic baselines and assimilate multi-modal data for GCS problems that are challenged by large degrees of freedom, nonlinear multiphysics, non-Gaussianity, and computationally expensive to evaluate fluid-flow and seismic simulations. To enable SBI for dynamic systems, a recursive scheme is proposed where the Digital Shadow{\textquoteright}s neural networks are trained on simulated ensembles for their state and observed data (well and/or seismic). Once training is completed, the system{\textquoteright}s state is inferred when time-lapse field data becomes available. Contrary to ensemble Kalman filtering, corrections to the predicted simulated states are not based on linear updates, but instead follow during the Analysis step of Bayesian filtering from a prior-to-posterior mapping through the latent space of a nonlinear transform. Starting from a probabilistic model for the permeability field, derived from a baseline surface-seismic survey, the proposed Digital Shadow is validated on unseen simulated ground-truth time-lapse data. In this computational study, we observe that a lack of knowledge on the permeability field can be factored into the Digital Shadow{\textquoteright}s uncertainty quantification. Our results also indicate that the highest reconstruction quality is achieved when the state of the CO2 plume is conditioned on both time-lapse seismic data and wellbore measurements. Despite the incomplete knowledge of the permeability field, the proposed Digital Shadow was able to accurately track the unseen physical state of the subsurface throughout the duration of a realistic CO2 injection project. To the best of our knowledge, this work represents the first proof-of-concept of an uncertainty-aware, in-principle scalable, Digital Shadow that captures the uncertainty arising from unknown reservoir properties and noisy observations. This framework provides a foundation for the development of a Digital Twin aimed at mitigating risks and optimizing the management of underground storage projects.},
	keywords = {Bayesian inference, conditional normalizing flows, deep learning, digital twin, GCS, Inverse problems, sequential Bayes, Summary Statistics, Uncertainty quantification},
	doi = {10.1093/gji/ggaf176},
	url = {https://slim.gatech.edu/Publications/Public/Submitted/2024/gahlot2024uads/paper.html},
	author = {Abhinav Prakash Gahlot and Rafael Orozco and Ziyi Yin and Felix J. Herrmann}
}
@conference {herrmann2024SIAMUQdt,
	title = {An Uncertainty-Aware Digital Twin for Geological Carbon Storage},
	booktitle = {SIAM Conference on Uncertainty Quantification},
	year = {2024},
	note = {(SIAM UQ, Trieste)},
	month = {03},
	abstract = {Arguably, Geological Carbon Storage constitutes the only truly scalable net-negative carbon emission technology. To mitigate its risks and optimize its operations, an uncertainty-aware Digital Twin is being developed. To leverage existing fluid-flow and seismic simulation and imaging capabilities, the envisioned twin combines techniques from sequential and simulation-based Bayesian inference to train its deep generative neural networks to draw samples from the posterior of the Digital Twin{\textquoteright}s state. Because these samples are conditioned on observed time-lapse field data, these twins are capable of capturing the dynamics of CO2 plumes and their uncertainty.},
	keywords = {Bayesian inference, CCS, deep learning, digital twin, GCS, Imaging, monitoring, SIAM, Uncertainty quantification},
	url = {https://slim.gatech.edu/Publications/Public/Conferences/SIAMUQ/2024/digital-twin},
	author = {Abhinav Prakash Gahlot and Rafael Orozco and Haoyun Li and Grant Bruer and Ziyi Yin and Mathias Louboutin and Felix J. Herrmann}
}
