Abstract
Accurate characterization and measurement of multiphase flows are important for efficiency and safety across industrial processes, including oil and gas production, chemical engineering, and carbon capture and storage (CCS). Due to inherent complexities such as spatial heterogeneity, transient structures, and slip conditions, existing measurement techniques face significant challenges. This thesis develops and validates advanced tomographic methods—specifically integrating gamma-ray tomography (GRT) and electrical capacitance tomography (ECT)—to enhance multiphase flow measurement accuracy. Through systematic experimentation and analysis, the research identifies optimized geometric configurations for gamma densitometry, demonstrating significant accuracy improvements with off-center and dual-beam configurations. It further evaluates cross-correlation and cross-spectrum methodologies for determining velocity profiles and identifies both strengths and limitations, particularly under stratified flow and high slip conditions. Moreover, while Venturi constrictions have been shown to homogenize multiphase flows, improving downstream measurement stability. The application of tomographic techniques in CCS processes is explored theoretically, revealing promising potential but underscoring the critical need for substantial experimental validation and technological optimization. Overall, this thesis advances multimodal tomography for multiphase flow measurements significantly, identifying clear pathways for future research and practical industrial implementation.