Capillary Pressure Measurement In Glass Bead Porous Media And Gas Diffusion Layers

Author : Ahmed S. Zankoor
Publisher :
ISBN 13 :
Total Pages : 0 pages
Book Rating : 4.3/5 (635 download)

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Download or read book In-situ Capillary Pressure and Its Interrelationships with Multiphase Flow Characteristics written by Ahmed S. Zankoor and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Flow and trapping processes of immiscible fluids in porous materials are regularly encountered in a wide range of applications including soil science, oil and gas recovery, geologic sequestration of CO2, and food processing. Such media are characterized by the existence of pore-scale interfaces which are strongly interrelated with the various phenomena and processes associated with these systems. In this dissertation, we develop and present a comprehensive understanding of several of these interrelationships through robust and cohesive experimental and computational research work. We first develop image analysis platforms for in-situ characterization of capillary pressure and wettability using x-ray computed tomography images of saturated porous media. These platforms incorporate practical high-performance computing and image analysis techniques to enhance their efficacy when applied to large-sized micro-CT images of extremely complex porous media. After a rigorous validation process, we use these platforms to analyze pore-scale fluid occupancy maps acquired during a wide range of multiphase core flooding experiments including complex processes such as steady-state two- and three-phase flow tests and various wettability and stress conditions. Our investigations show that a strong correspondence exists between the micro- (image-based) and macro-scale two-phase capillary pressure functions. However, the intermittent nature of the pore-scale displacement events contributes to the discrepancy between the multi-scale behavior. Similarly, during three-phase flow, the local capillary pressures corresponding to the invading phase comply with the macroscopic flow ratios. Nonetheless, more intricate pore-scale interactions such as hyperactive trapping and double displacement events further impact the local capillary pressure changes. Furthermore, capillary pressure gradients across the porous media are incorporated in the three-phase relative permeability measurements. In-situ capillary pressure measurements are also efficiently used to characterize the hydro-mechanical behavior of porous media under various wettability conditions. We find that wettability plays a crucial role in the interplay between the fluids' volume-pressure functions and the effective stress on sandpack samples. In particular, capillary pressure reductions and increases are observed and associated with interfaces being displaced or hinged in place in response to compression processes under water- and mixed-wet conditions, respectively.