الفهرس | Only 14 pages are availabe for public view |
Abstract The objective of the present work is to study the physical, thermodynamic and transport properties of heavy petroleum fractions and crude oils. This study resulted in a group of new methods for improving the predication accuracy of these properties and for extending the range of applicability of the currently available methods. The studied properties includes the viscosity, thermal conductivity, surface tension, density, enthalpy and PVT properties. A new simple and reliable empirical correlation for predicting the viscosities of heavy petroleum fractions is proposed. The new correlation is capable of predicting the viscosities of heavy petroleum fractions with mid-boiling points from 80 up to 550oC and for a wide range of viscosities (from 0.4 up to 260 mm2/s) and measurement temperatures (from 40 up to 200oC). This correlation is shown to be more accurate in the predication of heavy petroleum fraction viscosities than that of the best predictive methods in literature. A new corresponding states model for predicting trhe viscosity of heavy crude oils and peteroleum fractions is also proposed in this work. The model uses decane and eicosane as reference components for petroleum fraction of average molecular weight higher than 142. The viscosity of any component or fraction can be obtained from the viscosities of these two reference fluids (decane and eicosane) at the same reduced temperature and reduced pressure using the molecular weight as an interpolation parameter. This model showed better accuracy in predicting the viscosity than the model that uses one reference (methane) or two references (methane and decane), when the molecular weight is higher than 142. For estimating the thermal conductivity, a new empirical correlation, applicable to petroleum and coal liquid fractions is proposed. The new correlation requires the specific gravity as the only input to estimate the effect of temperature on the thermal conductivity. Good agreement between the predicted and experimental values has been found. |