Print Email Facebook Twitter Optimization Strategies of CO2 Injection for Sequestration and EOR Title Optimization Strategies of CO2 Injection for Sequestration and EOR Author Chen, Yuan (TU Delft Civil Engineering and Geosciences) Contributor Voskov, Denis (mentor) Degree granting institution Delft University of Technology Programme Applied Earth Sciences Date 2018-08-29 Abstract The current situation with green gas emission requires the development of low carbon energy solutions. However, a significant part of the modern energy industry still relies on fossil fuels. To combine these two contradictory targets, we investigate a strategy based on a combination of CO2 sequestration with Enhanced Oil Recovery (EOR) in the hydrocarbon reservoirs. In such technology, the development of miscibility is the most attractive strategy from both technological and economic aspects. Modeling of this process involves solving complex nonlinear problem describing compositional flow and transport in highly heterogeneous porous media. An accurate capture of the miscibility development usually requires an extensive number of components to be present in the compositional problem which makes simulation run-time prohibitive for optimization. Here, we apply a multi-scale reconstructing of compositional transport to the optimization of CO2 injection. In this approach, a restriction operator, based on the parametrization of injection and production tie-lines, is constructed following the fractional flow theory. This operator is tabulated as a function of pressure and pseudo-composition which then is used in the Operator-Based Linearization (OBL) framework for simulation. As a result, a pseudo two-component solution of the multidimensional problem will match the position of trailing and leading shocks of the original problem which helps to accurately predict phase distribution. Applying a simple prolongation operator, based on interpolation between injection and production compositions, a compositional solution with the correct reconstruction of two-phase region can be obtained.The reconstructed multicomponent solution can be used then as an effective proxy-model mimicking the behavior of the original multicomponent system. In this study, we use this proxy-model in the optimization procedure which helps to improve the performance of the simulation with the increasing intricacy of the reservoir model. In this work, the nonlinear constrained optimization function is applied to find optimal pressure values for CO2 injection process to acquire a highest Net Present Values (NPV). Starting with the limited number of the controls, the global extrema of the objective function can be determined from both full physics model and proxy model. The result shows that both models can converge to the similar extrema given various initial guesses. It is noting that for multicomponent system, the proxy model can also have salient accuracy to predict the NPV extrema compared with the original full model. As a result, the reconstructed proxy model can be significantly cheaper than a full conventional compositional model. An additional benefit of the proposed methodology is based on the fact that important technological features of CO2 injection process can be captured with lower degrees of freedom which accelerates the optimization process. Subject CO2 injectionOptimizationCompositional modelingEnhanced Oil RecoveryCarbon capture and storage To reference this document use: http://resolver.tudelft.nl/uuid:c6924adf-9f7b-4850-8099-056eb06bc11a Part of collection Student theses Document type master thesis Rights © 2018 Yuan Chen Files PDF Master_thesis_report_2018 ... n_Chen.pdf 2.51 MB Close viewer /islandora/object/uuid:c6924adf-9f7b-4850-8099-056eb06bc11a/datastream/OBJ/view