Development of Applicable and Suitable Methods for Control and Monitoring of Wax Formation by Determination of WAT for Crude Oil Transport in Pipelines

Determination of wax appearance temperature is a crucial specification in the transportation and storage of crude oil or heavy refinery products same as fuel oils. In this work, to determine wax appearance temperature different applicable methods were tested and developed. At first, the microscopic experiments were applied to different samples. Then the variation of viscosity versus temperature was monitored. To determine a feasible method to be applied in the fields, the variation of viscosity versus temperature was monitored. It was declared that at the wax appearance temperature a deep change in viscosity happened. Eventually, the wax appearance temperature of different crude oil including Iranian or heavy crude oil can be determined by the viscosimetry method. In the related experiments, the negative effect of water sediments and wax crystals was eliminated. It was also declared that the wax appearance temperature could be varied by variation of density, wax content, pour point, and asphaltenes of the samples. To correlate between input and output variables three different modeling methods were tested and implemented. The Artificial neural networks, Neuro-fuzzy, and regression models were tested to derive the most accurate correlation. The statistical studies approved that the regression models have suitable accuracy. The results of the regression model declared that the interaction effect of density and pour point and the effect of asphaltenes as one of the main input variables have the greatest impact on the wax appearance temperature.