White Paper: An Automatic Test Method with Improved Precision for Wax Appearance Temperature (WAT) of Crude Oils

One such method, Differential Scanning Calorimetry (DSC), detects WAT by measuring the difference in heat absorbed or released between a reference sample and the test sample at a given cooling or warming rate. The WAT is detected by a deviation of experimental data from the reference baseline and typically requires a significant amount of wax formation for sensible detection. Consequently, it may be difficult to obtain a reliable baseline and to pinpoint the deviation from the baseline, especially when the crystallization rate is low and signal noise overshadows thermal effects. Measured WAT tends to be lower than the actual temperature of initial wax formation, and interpretation of WAT by DSC depends on the subjective experience of the operator.