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

• Published in: Separation and purification technology Vol. 324; p. 124553
• Main Authors: Li, Boliang, Li, Binfei, Zang, Yunong, Zhu, Di, Li, Zhaomin, Ruan, Liwei
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.11.2023
• Subjects: Distillation; Flue gas; Heavy oil; SARA; Superheat; Distillation; SARA; Flue gas; Heavy oil; Superheat
• ISSN: 1383-5866; 1873-3794
• DOI: 10.1016/j.seppur.2023.124553

•With the assistance of flue gas, steam performed better in heavy oil distillation.•The mechanism of flue gas enhanced steam distillation on heavy oil was proposed.•The increased heat efficiency played the dominant role in enhanced distillation.•The hydrothermal cracking and allosterism of resin were intensified.•The distillation field of flue gas-steam was higher with the increase of superheat. 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 °C) and flue gas + steam distillation experiments at three superheat levels (0 °C, 48 °C and 100 °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 distillation 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.