Kantzas, ApostolosZhu, Guanying2023-07-172023-07-172023-07Zhu, G. (2023). Pressure response during gas diffusion in tight porous media (Master's thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca.https://hdl.handle.net/1880/116747In this thesis, the pressure change during countercurrent diffusion in the cyclic gas injection process was investigated. It briefly introduces the situation of climate change and the importance for considering Carbon Capture Utilization and Storage (CCUS) in the application of Enhance Gas Recovery. A real core and two compartments were used to represent the relationship in the system of fractures, porous media, and the gas reservoir. Three kinds of experiments, including single gas flooding in the core system, coupled gases diffusion without core in the system, and the most important one, coupled gases diffusion in different cores were carried out. The experimental system consists of two compartments and one core holder with the core samples in the middle. The initial conditions at the two sides of the core were set as an isobaric, both at around 40 psi (gauge pressure) to eliminate the convection effect and observing the pressure change caused by diffusion solely. Nitrogen, carbon dioxide and methane were used in different combinations to see the binary behavior in Scioto Sandstone and Torrey Sandstone. The general pressure trend for single gas flow in the cores is always decreasing at the very beginning and reaches a plateau due to the unsteady flow in the system. The binary gas behavior in no-core countercurrent diffusion is dominated by the heavier component. The binary gas behavior in the two sandstones is controlled by molecular weight at the beginning stage, but later it combines surface diffusion and sorption, rendering a more complex general behavior. The pore size also plays an important role if the pore diameter is comparable with the mean free path of the gas molecules. The response curve changes by varying the pore diameter and the critical surface area.enUniversity of Calgary graduate students retain copyright ownership and moral rights for their thesis. You may use this material in any way that is permitted by the Copyright Act or through licensing that has been assigned to the document. For uses that are not allowable under copyright legislation or licensing, you are required to seek permission.Countercurrent DiffusionSurface DiffusionSorptionCyclic Gas InjectionEngineering--Petroleummaster thesis