Modelling of wax deposition in sub-sea pipelines

Abstract

Wax deposition in sub-sea pipelines is a major concern in the oil industry. Wax precipitates in a pipeline when the temperature falls below a certain temperature called the Wax Appearance Temperature. As wax precipitates and deposits in a pipeline, the wax deposit can cause oil flow problems and reduce production efficiency. At critical conditions wax deposits in pipelines may damage production equipment or cause a production stoppage. In the past two or three decades, the challenge has been to develop and apply high-fidelity models for wax deposition. In this context, two promising models have recently been developed: that of Eskin et al. (2014) and that of Haj-Shafiei et al. (2014). This research report tries to solve and elucidate some of the key assumptions of these wax deposition models, through implementing them in the Python Programming Language. In investigating the significance of the shape of the Solubility Curve on wax deposition, a concave shaped solubility curve was found to exhibit the highest average deposition and the convex shaped solubility curve the lowest average deposition. The shape of the solubility curve also drastically affects the peak wax height with a concave shaped solubility curve forming the greatest wax peak. The results have shown that the description of the phenomenon of Wax deposition in undersea pipelines is difficult to grasp for anyone not familiar with the topic because of the complexity of the mechanisms involved. Often, the models are difficult to visualise owing to their multi-dimensional solution procedure and the interdependence of parameters. The resultant programs could be utilised to help illustrate the process of Wax deposition to Engineering students or professionals who do not have access to expensive proprietary software or who are less proficient with programming but interested in the field.