الملخص الإنجليزي
The exploration, recovery, transportation and purification of crude oil heavily depend upon the knowledge of the thermal and visco-elastic properties of these fluids under different temperature and pressure conditions. With the rapid development of the seismic and well logging technologies, procurement of detailed data of hydrocarbon liquids is getting increasing attention. In the present work, we have used four different laboratory techniques such as: (i) the Differential Scanning Calorimeter that is used to measure the specific heat at constant pressure, (ii) the Ultrasound interferometer is used to determine the velocity of propagation of compressional wave, (iii) Cannon-Fenske Viscometer is utilized to measure viscosity and (iv) the Anton Paar Density Meter is used to determine the density in'crude oils. All physical properties are measured over a wide range of temperature varying from room temperature to 70°C. Three different crude oil samples used in our measurements have been procured from different oil fields of Sultanate of Oman, namely Lekhwair, Fahud and Karim. Our determined values of API (American Petroleum Institute) gravity suggest that the three different oil samples belong to light, medium and heavy oils.
These directly measured functions are then used to derive other thermal and visco elastic functions within the framework of "Theory of Deformation". Equation of motion has been derived in terms of stress and strain components of the deformable media. This has been utilized to compute the stress components in cylindrical pipelines that are typically used for the transportation of crude oils. The equation of motion has also been extended to study the propagation of dilatational waves in fluids and the effect of viscosity. The resulting equations have been combined to the thermodynamic equations to obtain the various thermo- visco-elastic functions, such as, adiabatic and isothermal compressibility, -coefficient-of volúme expansion, acoustic impendance, Grüneisen parameter, Debye temperature, ratio of the specific heat, shear wave velocity, attenuation parameter and the activation energy of the three different oil samples.
