Wax deposition rate model and calculation examples for Aershan-Saihantala Oil Pipeline

Severe wax deposition of the Aershan-Saihantala Oil Pipeline leads to more frequent pigging and failure of pig to reach the desired position. In this aspect, this paper discusses the calculation approach and model of wax deposition rate and the way to build the model. Given the influence of oil flow on wax deposition and based on Fick diffusion rule, the wax deposition rate is re-defined. Through theoretical analysis and experimental research, the relationship among wall shear stress, wall temperature gradient and inclination coefficient of wax deposition is identified. Considering the basic properties of crude oil transported via the Aershan-Saihantarla Oil Pipeline, the model of wax deposition rate is established with wax deposition prediction software to predict the distribution of wax deposition rate along pipeline under different operating conditions. The research results are very constructive to optimizing the temperature of crude oil incoming the terminals.