(261d) Dynamic Structure Breakdown and Recovery in Model Wax Systems

Understanding of wax formation in hydrocarbon systems is of critical importance for flow assurance applications.  In this study, a model wax in a model oil is precipitated under a series of isothermal conditions and examined using shear and oscillatory rheology.  An increase in plastic viscosity indicates the formation of wax crystals and the emergence of a yield stress indicates a percolating network of wax.  Oscillitory rheology is used to probe the shear modulus and yield stress of this network while stepped shear rate experiments and observation of the time-dependent shear stress is used to characterize the breakdown and rebuilding of the wax network structure.  To compliment these observations, acoustic spectroscopy is used to monitor the initial wax particle size along with flow-loop, visualization experiments to provide quantitative precipitation and deposition behavior in flowing systems. The insight presented in this work will inform fundamental modeling efforts that are targeted to predict the flow behavior of wax systems over a variety of shear conditions.