Speaker
Description
Accurate simulation of CO2 sequestration in deep saline aquifers requires a consistent treatment of history-dependent processes that control immobilization and trapping, including capillary-pressure and relative-permeability hysteresis as well as dissolution-driven feedback on phase saturations. Operator-Based Linearization (OBL) is an efficient and robust framework for large-scale thermal-compositional flow simulation. However, the standard formulation implicitly assumes reversibility of thermodynamics because operator evaluation depends solely on the instantaneous thermodynamic state (e.g., pressure, composition, and temperature). This limitation restricts the direct use of conventional OBL for irreversible or path-dependent physics.
In this work, we propose an augmented OBL framework that embeds history variables into the operator parameter space while preserving the structure and dimension of the fully implicit Jacobian matrix. The central idea is to treat selected history coordinates as additional local state descriptors for operator parameterization, so that operator values and consistent derivatives become both state- and history-dependent without ad hoc switching or external correction steps. As a first application, we develop a new fully implicit hysteresis algorithm in which the maximum gas saturation is introduced as a local history variable and updated dynamically to capture drainage--imbibition transitions. The algorithm further incorporates feedback from CO2 dissolution, allowing the hysteretic state to evolve consistently with compositional mass transfer and phase behavior.
We validate the proposed approach against implementation in academic and commercial simulators, demonstrating close agreement in pressure and saturation evolution, hysteretic scanning behavior, and trapping metrics under comparable hysteresis settings. In addition, a sensitivity analysis of the operator parameterization quantifies how the resolution of the augmented parameter space governs both accuracy and computational cost, providing practical guidance for selecting discretization levels in reservoir-scale studies. Numerical experiments with various types of models demonstrate that the method effectively captures key hysteretic effects while retaining the computational advantages of OBL. Overall, the augmented OBL framework provides a practical and accurate route for incorporating history-dependent physics into compositional simulations of CO2 storage in saline aquifers.
| Country | The Netherland |
|---|---|
| Green Housing & Porous Media Focused Abstracts | This abstract is related to Green Housing |
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