The Effect of Shear Stress on Wax Deposit Thickness with and without Spiral Flow

The main objective of this research is to estimate and discuss the effect of shear stress on wax deposition in the hydrocarbon pipeline. Two sets of experimental data were used to analyse the effect of shear stress on wax deposition with and without spiral flow at different inlet coolant temperatures and different flow rates. A new mathematical model was developed during this study to estimate the shear stress, because of the spiral flow, on wax deposition. The concept of this model was based on the forces that influence on the crude oil flow in the pipe, with and without inserting the twisted plate to create spiral flow, depending on the pressure drop along the pipe. The results are presented that, increasing the shear stress, because of the effect of the spiral flow, leads to decrease the wax deposit thickness with increasing the pressure drop while the shear stress decreased in the case of crude oil flow without spiral flow leading to increasing the wax deposit thickness. On the other hand, increasing the inlet coolant temperature leads to decrease the shear stress and wax thickness because of decreasing the value of the crude oil viscosity. This developed model can be considered as a base model for similar studies to calculate the shear stress in the fluid flow pipelines using the twisted plate to create spiral flow.