Morphology of Wax\nCrystals Affects the Rheological\nProperties and Thermal Conductivity of Waxy Oils

The rheological properties and thermal conductivity of\nwaxy crude\noils are critical factors influencing calculations for pipeline shutdown\nand restart procedures. In this study, the influence of wax content\nand PPD on wax precipitation characteristics, rheology, and the thermal\nconductivity of waxy oils is explored. The intricate mechanism through\nwhich the microscopic morphology of wax crystals affects the rheology\nand thermal conductivity is unveiled. The results indicate a significant\ncorrelation between the rheology and the thermal conductivity of the\nwaxy oil. Both wax content and PPD play pivotal roles in determining\nthe thermal conductivity and rheology of waxy oils by modulating the\noverlap of wax crystals and the effective solid phase content. Specifically,\nsmaller crystal sizes coupled with a larger aspect ratio augment the\nintersection points between wax crystals and expand the solvation\nlayer volume fraction. Consequently, this enhances the gel structure\nand viscosity of the waxy oil on one hand while broadening thermal\nconduction pathways and boosting the effective solid phase content\non the other, ultimately elevating thermal conductivity. The study\nclarifies the mechanism underlying the correlation between rheological\nproperties and thermal conductivity in waxy oils, offering significant\ninsights into developing models of rheology and thermal conductivity\nduring gelation.