Waxes

Waxes are complex mixtures of solid hydrocarbons that freeze out of crude oils if the temperature is low enough. Under the conditions of interest to the oil industry, waxes consist mainly of normal paraffins.

The Infochem thermodynamic wax module includes the Coutinho model, which represents wax as a solid solution. It requires that the normal paraffins are explicitly present in the fluid model, although the n-paraffin content can be estimated if necessary. The model gives good predictions of waxing behaviour, both wax appearance temperature and the amount of wax precipitated at different temperatures. The model can be applied to both live and dead oils.

Modelling wax deposition, the formation of a wax layer on the inner surface of pipeline walls, requires models for heat and mass transfer, fluid flow and shear removal in addition to the thermodynamic wax model. This is incorporated in our FloWax package.

For more information on wax thermodynamics please see our Wax leaflet, case studies or publications. For information on wax deposition please see our Wax deposition leaflet.