Factors Influencing Wax Solubility

摘要

Wax deposition in pipelines during crude oil production is a critical issue for the petroleum industry. Deposition is a relatively complex process believed to be controlled by a diffusion mechanism and influenced by shear in the pipeline flow. The key driving force behind diffusion and the deposition process is the thermodynamic equilibrium of the solubility of the wax in the crude oil. Hence, the ability to adequately understand and model wax solubility plays an important role in understanding and modeling pipeline wax deposition. An improved understanding can also contribute to developing better inhibition and remediation methods. Several new solubility measurements of model n-alkanes in various solvents are presented in this paper to provide an overview of factors influencing wax solubility. The effects of the properties of the wax (carbon number, chain length, thermophysical properties) and solvent (molecular size, associations) are illustrated in the measurements. It is also shown that, although not perfect, two-dimensional solubility parameter theory can be used to qualitatively gauge the strength of solvents towards wax.