Analysis of the characteristics of flue gas foam seepage and its influencing factors

The flue gas foam-assisted steam flooding technology is beneficial to inhibit the steam channeling, delay the steam overriding and improve the heat utilization rate. At the same time, it is also conducive to carbon dioxide storage, which has a broad application prospect. However, the current research on the seepage characteristics and influencing factors of flue gas foam-assisted steam flooding is insufficient. In this paper, the sand pack flooding experiments were carried out by changing the gas-liquid ratio, injection rate, temperature, permeability and other parameters. The results showed that in the case of low gas-liquid ratio, the number and size of foams are small and the connectivity between foams is poor. When the gas-liquid ratio is high, the gas-phase composition is high so that gas channeling occurs and the plugging effect is reduced. Experiments showed that when the gas-liquid ratio is 2:1, the resistance factor is the largest and the plugging performance is the best. When the injection rate is 3mL/min, the foam is stable, which is beneficial to the foam plugging. When the injection rate is lower than 3 mL/min, the foam is sparse and the foam liquid film is thin so that the plugging effect is poor. When the injection flow rate is higher than 3 mL/min, more foam with smaller size will be formed under the influence of shear action, and the Jamin effect on the pore throat will be weakened, which is difficult to be plugged by the foam system. With the increase of experimental temperature, the intermolecular force of the solution was strengthened, the foam volume was enlarged and the liquid film was thinned so that the foam stability and the plugging performance were weakened. Oil saturation has a greater impact on the plugging ability of the flue gas foam. The higher the oil saturation, the weaker the plugging ability is. The research can provide reference for the application of flue gas foam plugging technology.