| This study investigates improvement to the basic viscosity model "Friction Theory Viscosity Model with Kc Tuning" that was developed for light oils by Quinones-Cisneros et al. 1-8 , in order to extend the model to heavy oils. First, it analyzes a recently developed modification "Friction Theory Viscosity Model with Kz-Kc Tuning". Second, it provides an improved modification, supported by calculations.;An objective of the present research work is to propose a suitable modification to the basic viscosity model i.e. "Friction Theory Model with K c Tuning", which can enhance the accuracy of the model in predicting the viscosity of heavy oils. A FORTRAN Program was developed and after ascertaining its accuracy, the proposed modification in this research was incorporated. The program was then applied to predict the Viscosity of heavy oil, using data from the literature. The predicted viscosity values were compared with experimental results and viscosity values calculated using the original "Friction Theory Viscosity Model with Kz-K c Tuning".;After analysis, it is concluded that the proposed tuning (tuning of mixing exponential parameter epsilon) of the basic model not only reduced the error level significantly for pressures below the saturation pressure, but the overall accuracy was also improved for heavy oils. Hence, for heavy oils, "Friction Theory Viscosity Model with Kc Tuning" coupled with simultaneous tuning of the mixing exponential parameter, epsilon, is highly recommended.;Based on a literature search, it was found that "Friction Theory Viscosity Model with Kc Tuning" gives good results for light and lower medium oils. Application of this model to heavy oils results in significant errors, particularly for pressure below saturation pressure. It was also found that the "Friction Theory Viscosity Model with K z-Kc Tuning" did not give satisfactory performance in the case of heavy oils. Large deviation was observed for predicting the viscosity at a pressure below the saturation pressure. |
