Effects of pressure depletion rate, solvent, and surfactant on non-equilibrium reactions in foamy oil

Abstract

This research employed a visual method to explore the behaviour of foamy oil in heavy oil systems. A Hele-Shaw cell was designed for observing the volumetric expansion of foamy oil as the system pressure decreased. This approach facilitated an examination of foamy oil's interface evolution under pressure depletion and an analysis of bubble sizes and their distribution. Using Minitab, 15 experiments were strategized, aimed at observing the distribution of bubbles and their stability during the foamy oil process. The investigation also extended to studying the influence of surfactants, solvent type, and pressure reduction rate on foamy oil. The findings suggest that a high concentration of surfactant, a high percentage of CO₂ solvent, and a rapid pressure drop rate all contributed to the generation of microbubbles and enhanced volumetric expansion and stability of foamy oil. However, in light of the conducted energy analysis, a lower rate of pressure reduction is recommended. Finally, the conditions of the 15 experiments were applied to the CMG to derive two non-equilibrium reactions for bubble generation and collapsing. The reaction rates are such that they relate bubble generation to the pressure reduction rate of the process and bubble resistance to collapsing to the surfactant concentration of the foamy oil.