Correlation development for the viscosity reducing effect of solvent in an enhanced oil recovery (EOR) process

Abstract

Bitumen is characterized by high viscosities and requires diluent to reduce its viscosity to about 400 cp for pipeline transportation. In this study, viscosity data on heavy oil-solvent binary and ternary mixtures has been correlated. The data consist of data obtained from taking measurements of seven heavy petroleum samples, both bitumen and heavy oils, diluted with five hydrocarbon solvents and binary and ternary mixtures so to reduce the viscosity of the heavy petroleum to pipeline viscosity. The amount of solvent varied from 5-60%.Measurements of viscosity were made at a variety of temperatures ranging from 10-80°C. Thus, the entire effect of temperature on the viscosity of binary and ternary mixtures of bitumen diluted with primary and secondary solvents was evaluated. A total number of 650 data points was obtained, with the viscosity ratios between 10 2 and 10 6 . Viscosity correlation based on the combination of equations from API-TDP and Latour et al (Pet. Sci. Tech. 18(1&2) pp.1-14, 2000) was developed. The results indicate that the correlation fitted the data best compared to other models. The average absolute deviations from 2.1% to 5.2% for binary mixtures and from 1.5% to 2.6% for ternary mixtures were obtained. The equation takes into consideration the combined interaction effects of temperature and solvent on the heavy oil viscosity.