Chemical Engineering
Hossein Hejazi; Behrouz Bayati; Mohsen Mansouri
Abstract
This study investigated the effect of ethylene-vinyl acetate (EVA) as an inhibitor on wax appearance temperature (WAT) of crude oil in the Iranian oil field using the differential scanning calorimetry (DSC) method. The effect of EVA on the morphology of crude oil wax crystals was examined by a system ...
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This study investigated the effect of ethylene-vinyl acetate (EVA) as an inhibitor on wax appearance temperature (WAT) of crude oil in the Iranian oil field using the differential scanning calorimetry (DSC) method. The effect of EVA on the morphology of crude oil wax crystals was examined by a system equipped with an ocular microscope. The EVA inhibitor has an outstanding performance in reducing the wax appearance temperature of crude oil and prevents the crystallization process and the connection of the growing wax crystals to form a network structure by adsorbing on them. Adding 800 ppm of the EVA inhibitor caused the most significant decrease in the WAT of crude oil at a rate of 26.13 °C and formed smaller crystals and weaker structures at this concentration. Therefore, 800 ppm of the EVA inhibitor was selected as the optimal value.
Petroleum Engineering
Yavar Karimi; Ali Reza Solaimany Nazar
Abstract
The influences of several operating factors on the viscosity of the Isfahan refinery waxy crude oil sample are studied through conducting some rheological shear rotational tests. The Taguchi design method is adopted to determine the impact of factors such as shear rate, temperature, cooling rate, wax ...
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The influences of several operating factors on the viscosity of the Isfahan refinery waxy crude oil sample are studied through conducting some rheological shear rotational tests. The Taguchi design method is adopted to determine the impact of factors such as shear rate, temperature, cooling rate, wax content, and asphaltene content on the viscosity of the waxy crude oil. The results show that temperature with a contribution of 53.61% is the most influential factor. The wax content, shear rate, and asphaltene content have a contribution of 20.86, 14.75, and 3.11% respectively. The cooling rate does not have a statistically significant effect on the viscosity. The results of the rheological oscillatory tests confirm that the temperature and wax content change the viscoelastic properties of the waxy crude oil completely. An increase in the wax content from 12 to 22 wt.% raises the wax appearance temperature (WAT) from 19.1 to 34.9 °C and improves the gel point from 13 to 34.1 °C. By decreasing the temperature or increasing wax content, the viscoelastic nature of the oil sample changes from a viscoelastic fluid to a viscoelastic solid.