Experimental study of the distillation mechanism during coinjection of flue gas and steam for heavy oil development

As an industrial waste gas, flue gas achieves a favorable performance in assisting steam to develop heavy oil, where steam distillation plays a crucial role. However, there are few studies of the physical changes in heavy oil and the distillation mechanism during flue gas-steam coinjection, which seriously inhibits flue gas applications in oil fields. Herein, the comparative steam and flue gas + steam distillation experiments (superheat of 120 degrees C) and flue gas + steam distillation experiments at three superheat levels (0 degrees C, 48 degrees C and 100 degrees C) were conducted using a high-temperature and high-pressure distillation kettle. The carbon number distribution of distillates during distillation and heavy oil properties before and after distillation were compared and analyzed. The results showed that the effect of flue gas on steam distillation was significant, and the flue gas + steam distillation yield reached 20.24%, which was 3.88% higher than that of pure steam. With increasing steam superheat during flue gas-steam coinjection, the carbon number distribution range of the distillates gradually expanded, the distilla-tion yield gradually increased, and the flue gas + steam distillation yields under the three superheat levels were 13.5%, 15.49% and 16.59%, respectively. Compared to pure steam distillation levels, resin hydrocracking and allosterism in the flue gas + steam distillation process were intensified, the resin content decreased, and the saturate, aromatic and asphaltene contents increased. Moreover, the heat exchange and heat utilization rates between steam and crude oil were improved under the flue gas effect, and the upper limit of the distillate carbon number significantly increased. The research results are significant for further refining the mechanism of flue gas enhanced steam development of heavy oil.

Automated summary

In this study, the effect of flue gas on steam distillation of heavy oil was investigated. The results showed that the yield of flue gas + steam distillation was 3.88% higher than that of pure steam distillation. Increasing steam superheat during flue gas-steam co-injection expanded the carbon number distribution range of the distillates and increased the distillation yield. The research findings are significant for understanding the mechanism of flue gas enhanced steam development of heavy oil.