Wax Appearance Temperature Prediction with Wax Inhibitor of Crude Oil from the North of Thailand

Abstract

Waxy crude oil is one of the crucial problems for the flow in the pipeline of crude oil. One critical characteristic used in determining a point where wax started to form is wax appearance temperature (WAT). However, the WAT cannot be easily determined. Therefore, it is convenient if the WAT could be predicted beforehand. This study mainly focuses on the determination of WAT and modification of existing equations, Ronningsen equation and Al-Roomi equation, to predict WAT. To achieve the objective, the nonlinear regression analysis has been used to modify the equations. The parameters in the equations are changed to match with the parameters from the actual laboratory experiment, which are the concentration of inhibitors, shear rates, and temperatures. The WATs obtaining from modified equations are used to compare with the WATs of waxy crude oil from experiment. For WAT prediction by modified equations, the results show the acceptable compatibility in the case of the modified Ronningsen equation. However, modified Al-Roomi equation is not suitable to predict WAT of waxy crude oil. The modified Ronningsen equation is suitable to use when there is sufficient concentration of inhibitors added to the crude oil. Also, the results show that 0.22 to 3.84 percent error has been obtained.