Determination of Wax Appearance Temperature in Various Crude Oils

Abstract

To predict the tendency of oil to form paraffin deposits there is applied the rheological research method, phase transitions of paraffins research in five various crude oils of the oil fields in Udmurtia and Syria. The wax appearance temperature (WAT) was determined based on the viscosity-temperature curves of the studied crude oils. The comparative analysis of the WAT values was conducted by the rheological method and the calculation method, based on ten different correlation equations. It is emphasized that the smallest indicator of the absolute deviation of the calculated WAT value from the experimental one was obtained for the correlation equations based on the content of solid paraffinic hydrocarbons. It was found that heavy resinous and highly resinous oils with a paraffin content of more than 5% were characterized by the highest values of WAT, which determines their closeness to paraffin saturation in reservoir conditions and a high tendency to form paraffin deposits.