An Improved Viscosity Correlation for CO2/Reservoir Oil Systems

SUMMARY This paper presents a correlation for predicting viscosities of CO2/-hydrocarbon mixtures. Viscosities were measured with a piezoelectric quartz crystal over a range of conditions from 32.2°C [90°F] to 121.1°C [250°F] and 6.89 MPa [1000 psi] to 34.5 MPa [5000 psi]. Crude oils and several synthetic oils were used in the study. The Lohrenz, Bray, and Clark (LBC) correlation was modified using the Corresponding States Principle coupled with new mixing rules to include mixtures with CO2 concentrations of up to 98 mole%. The new correlation showed about 70% improvement in average absolute deviation compared to the LBC procedure. The new correlation is expected to improve our capability to predict oil recovery performance both in the laboratory and in the field.