Glass Transition in Crude Oils Under Pressure

The transition to the glassy state in crude oil has been investigated at high pressures by the transient hot-wire method and differential scanning calorimetry. The nine samples investigated represent the most common types of crude oils and their fractions. The range of pressures was from atmospheric to 2GPa in the temperature range of 150–370 K. The pressure dependence of the glass transition in crude oils and oil fractions (dTg/dp) depends upon the viscosity of the system.