Experiences in numerical simulation of wax deposition in oil and multiphase pipelines: Theory versus reality

Wax deposition in pipelines transporting waxy oils and multiphase fluids is a significant flow assurance issue. The main problems caused by wax deposition include dramatic viscosity increase or complete gelling of crude oil. The present study shows a review of existing literature references concerning the problem of wax deposition, the main driving forces behind the phenomenon and the relative mathematical models developed. In addition, the application of the main mathematical models to real field data is presented in order to compare the numerical results with measured field values. In fact, wax deposition models, generally, are validated using experimental data, obtained from laboratory deposition tests; anyway, since the scale-up of the data to the real field cases is a problem, it is more advisable to compare models' predictions to real field data. Four sets of field data have been simulated, two involving one phase wax deposition and two related to wax deposition from multiphase flow.