Vargas, Francisco M2019-05-172019-12-012018-122018-11-12December 2Zhang, Jieyi. "Viscosity Modeling of Complex Fluids." (2018) Diss., Rice University. <a href="https://hdl.handle.net/1911/105894">https://hdl.handle.net/1911/105894</a>.https://hdl.handle.net/1911/105894Viscosity is an important fluid property that is widely used in many scientific and engineering disciplines. The viscosity of different substances and mixtures can vary orders of magnitude because of factors that affect the intermolecular interactions, such as the non-ideality of mixtures due to molecular size and shape differences, the physiochemical properties of its constituents, and its temperature and pressure. Since the intermolecular interactions can vary significantly from one fluid to another, the viscosity modeling and prediction procedure needs to be studied on a fluid-specific basis. The interplay of these factors makes predicting the viscosity of fluids difficult. Despite decades of research in this area, accurate prediction of viscosity for a wide range of substances and mixtures remains a challenge. The work presented here investigated four aspects of the viscosity modeling of complex fluids that covers reservoir fluids, nonpolar hydrocarbons, and aqueous glycols. Existing methodologies were evaluated and expanded for nonpolar hydrocarbon mixtures with applications in modeling reservoir fluids, which contributes to the understanding of the combined effect of characterization, equation of state, and viscosity models on the accuracy. In addition, a methodology based on simple optical or volumetric measurement at typical laboratory environment was developed for predicting the viscosity of pure and mixture of nonpolar hydrocarbon that are advantageous in areas such as cost and logistics. Furthermore, existing methodologies were assessed and extended for aqueous glycols mixtures, which revealed their capabilities and the limitations. Finally, a methodology was developed for accurate prediction of aqueous glycol systems with terminal hydroxyl groups based on the observed universal behavior, offering a unique approach to modeling the complex behavior of such systems. The advances presented in this dissertation furthered the current understanding and expanded the available options for the viscosity modeling of complex fluids, potentially enabling wide applications across industries.application/pdfengCopyright is held by the author, unless otherwise indicated. Permission to reuse, publish, or reproduce the work beyond the bounds of fair use or other exemptions to copyright law must be obtained from the copyright holder.viscosityfluidThesis2019-05-17