Behaviors of Foamy Oil Flow in Solution Gas Drive at Different Temperatures

Abstract

The role of foamy oil flow in the cold production of heavy oil in a solution gas drive has been extensively studied in recent years. In this study, solution gas drive tests were performed in micromodels and sandpacks to investigate not only the behaviors of foamy oil flow at different temperatures but also the effect of temperature on displacement efficiency. The micromodel tests indicated that three flow states existed with the solution gas drives at 54.0 and \(100.0\,^{\circ }\hbox {C}\), which were an oil phase flow, a foamy oil flow and an oil–gas two-phase flow. The micromodel test at \(150.0\,^{\circ }\hbox {C}\) showed a continuous gas phase, while the two-phase oil–gas flow was formed after the oil phase flow. The sandpack test results showed that foamy oil can improve the performance of a solution gas drive at temperatures below \(120.0\,^{\circ }\hbox {C}\). Unfortunately, the behavior of the foamy oil flow was not readily observed in the sandpack test at \(150.0\,^{\circ }\hbox {C}\). The results of this study also showed that there is an optimum temperature at which the highest oil recovery can be obtained in the solution gas drive and that the relative permeabilities of the gas and oil can be estimated from the sandpack test results. When the gas saturation is less than the cutoff gas saturation, the relative permeability ratio of the gas and oil at a higher temperature is higher than that at a lower temperature; the mobility ratio at \(100.0\,^{\circ }\hbox {C}\) was also shown to be lower than that at 54.0 and \(150.0\,^{\circ }\hbox {C}\).