Implementation and Validation of Gravity Effects in a Pore-Network Solver

Bachelor Thesis from the year 2012 in the subject Engineering - Mechanical Engineering, grade: 1.0, Swiss Federal Institute of Technology Zurich, language: English, abstract: With the aid of a gravity implemented pressure solver and a pore network model, we have been able to simulate and analyze the mechanism of fluid displacement in porous media. Exemplarily, the pressure solver is used to simulate the injection of ethyl acetate and heptane into the water and glass beads filled CCS-showcase, which is an experimental setup to understand the process behind carbon dioxide storage. In a first step, gravity effects are implemented into the flow rate and thus change the local capillary pressure by altering the wetting and nonwetting saturation. The validity of this approach is shown by a series of Test Cases which are stepwise expanded to more complex pore networks. A parameter study is done to understand the spreading behavior of less dense, less viscous and with high interfacial tension afflicted nonwetting fluid injections of different flow rates. Results of this parameter study allow comprehending the influence of capillary, gravity and viscous forces during fluid displacement in the CCS-showcase. For this reason the showcase glass beads are modeled by the conceptual approach of the general site bond correlated pore network model hypon, which relates pore throat and pore body size distribution to generate a regular isotropic pore network as simulation basis. Finally, the similarity in the plume of the experiments and simulations is investigated and shows consistency in the case of fluids with low interfacial tension like ethyl acetate, but requires a more precise capture of the network properties for fluids with high interfacial tension and low viscosity like heptane.