Efficient simulation of CO2 migration dynamics in deep saline aquifers using a multi-task deep learning technique with consistency.

CO 2 sequestration and storage in deep saline aquifers is a promising technology for mitigating the excessive concentration of the greenhouse gas in the atmosphere. However, accurately predicting the migration of CO 2 plumes requires complex multi-physics-based numerical simulation approaches, which are prohibitively expensive due to highly nonlinear coupled governing equations and uncertainties in heterogeneous spatial parameter distributions. To address this challenge, we developed an end-to-end deep learning workflow employing encoder–decoder architectures with residual network (ResNet) to efficiently predicts the spatial–temporal evolution of the solution CO 2 -brine ratio (R s) and gas saturation (S g) – the two essential tasks for quantifying the amount of trapped CO 2 – given heterogeneous permeability fields as input. Specifically, we introduce a general multi-task learning with consistency (MTLC) framework to simultaneously predict R s and S g. The MTLC model leverages related tasks with less computational expensive labeled datasets to improve generalization ability. In our study, predictions for multiple tasks from the same permeability realization are not independent but expected to be consistent, as the proposed framework utilizes data-driven cross-task consistency constraints to augment learning of related tasks. Our deep learning model is trained based on physical trapping mechanisms, which play a dominant role in the CO 2 migration process. The results demonstrate that the MTLC model with joint learning yields more accurate predictions and improved generalization for predicting CO 2 migration in several test cases. Furthermore, our workflow is 1 0 5 times faster than a high-fidelity physics-based numerical simulator, making it a viable alternative for field-scale applications. • A novel Multi-Task Learning with Consistency (MTLC) framework is proposed for CO 2 storage. • MTLC improves predictive accuracy by utilizing the relationship between tasks. • Comparisons demonstrate MTLC's effectiveness with limited data. • Accurately predicted the amount of CO 2 trapped by various mechanisms with MTLC. [ABSTRACT FROM AUTHOR]