Modelling of wax deposition by perturbed hard sphere chain equation of state

Abstract

This article presents a model to predict the wax appearance temperature (WAT) and the quantity of wax deposition in eight different n-alkane mixtures using a correlative technique. The perturbed hard sphere chain equation of state (PHSC EoS) was employed in conjunction with the multi-solid model to describe the liquid-liquid and solid-liquid equilibria. The results are compared with experimental data. The results showed that PHSC EoS for some mixture of n-alkanes can perceptibly outperform the sole solid solution theory, improving the modelling of wax deposition quantities and wax appearance temperature by giving predictions closer to experimental values.

Wax and Wax–Hydrate Deposition Characteristics in Single-, Two-, and Three-Phase Pipelines: A Review

“…Because of the shearing force of pumps or valves and the presence of natural emulsifiers such as glial and asphaltene in crude oil, the medium in the pipe can easily form emulsions in the oil–water transportation, and the most common one is the oil-in-water (W/O) emulsion. , Therefore, for the wax deposition process in oil–water flow, its influencing factors are more complicated than the single-phase pipeline wax deposition process. According to the related research, the existence of a dispersed phase will obviously change the wax deposition characteristics and make it difficult to predict the deposition process. , …”

“…According to the related research, the existence of a dispersed phase will obviously change the wax deposition characteristics and make it difficult to predict the deposition process. 95,104 Couto et al 105 used cold fingers to study the influence of water content on wax deposition when the total volume of the water-in-oil emulsion remains unchanged, and they found that, as the water content increases, the wax deposited quicker, and it is believed that the shear strength during the preparation of the emulsion has no effect on the wax deposition process. However, note that, because the total volume of emulsion remains unchanged during this experiment, the change of wax deposition rate in the experimental results cannot be attributed to the increase of water content, because a decrease in oil phase volume may also lead to the above-mentioned changes.…”