Temperature Dependent Thermodynamic and Thermo-Elastic Properties of Crude Oil

The density, ultrasound velocity and specific heat capacity at constant pressure of three crude oil samples were measured between temperatures of 20°C to 60°C. The experimental tools used were, densitometry, ultrasonic interferometry and differential scanning calorimetry to evaluate the density, ultrasound velocity and the specific heat capacity, respectively. These measurements are further used to evaluate the adiabatic compressibility, coefficient of volume expansion and acoustic impedance of these three samples. To determine other important properties for the samples, a fundamental relationship between thermodynamic and thermo-elastic properties was determined. Using this relationship, the specific heat at constant volume, the ratio of specific heats and the isothermal compressibility was ascertained. Finally, to show the potential of the laboratory data, the temperature dependence of pressure, a relatively difficult measurement to make under reservoir conditions, was calculated using the isothermal compressibility and the coefficient of volume expansion.