Foamy oil viscosity measurement

Abstract

The rheological studies of gas-oil dispersion are essential for understanding the foamy oil flow behaviours related to high production rates in many heavy oil reservoirs. The viscosity of gas-oil dispersion is one of the critical parameters that influence the recovery in solution gas drive process. Only a few laboratory experimental studies have been carried out to investigate the effects of live oil viscosity and foam quality on the apparent viscosity of the foamy oil during the depressurization process. As for gas-in-oil dispersion, the continuous phase is the supersaturated live oil during the depressurization process. It is essential to quantify the in-situ foam quality to verify the viscosity models for the foamy oil viscosity calculation under pressure conditions. However, none of those previous experimental studies has directly measured the in-situ foam quality, to the best of our knowledge. Hopefully, this study developed a novel visualization-based experimental method to measure the in-situ foam quality under reservoir conditions in both CO2-heavy oil system and methane-heavy oil system. The foam quality under non-equilibrium conditions was first measured and analyzed by a real-time visualization chamber system. Besides, the viscosity models for the foamy oil viscosity calculation have been generated in both CO2-heavy oil system and methane-heavy oil system. The viscosity correlations developed in this study are capable of predicting the in-situ viscosity of gas-oil dispersion in the solution gas drive process on both laboratory and field scales.