非凝析气体强化蒸汽深部换热机理研究

为研究蒸汽驱过程中非凝析气体强化蒸汽深部换热机理,利用一维物理填砂模型开展非凝析气体辅助蒸汽驱模拟实验,并通过冷凝传热实验分析了非凝析气体对水蒸气冷凝换热的影响。实验结果表明,纯蒸汽注入时,蒸汽与多孔介质的换热速率快,蒸汽热波及范围较小,随着非凝析气体的加入,蒸汽热波及范围增大,深部油藏得到加热,有效改善蒸汽的热利用率。与纯蒸汽冷凝时相比加入非凝析气体之后,凝结液滴的生长和脱落速度慢,能形成较大液珠,液珠的存在阻碍了蒸汽换热,非凝析气体抑制了蒸汽冷凝。深入认识非凝析气影响蒸汽传热机理,对非凝析气强化蒸汽热传递以及提高蒸汽热利用率具有指导意义。

Heat Transfer Enhancing Mechanism of Deep Steam with Non-Condensate Gas

In order to study the heat transfer enhancing mechanism of deep steam with non condensate gas in steam flooding, a 1D physical sand pack model was used to conduct a non condensate gas assisted steam flooding simulation experiment. The effect of non condensate gas on the steam condensation heat transfer was analyzed by a laboratory condensation heat transfer experiment. Experiment indicates that the pure steam injection shows a high steam medium heat exchange rate and a relatively small heat spread range. With the adding of non condensate gas, the steam heat spread range increases and the deep reservoir is heated, which effectively improve the steam heat utilization rate. Comparing with pure steam condensation, the growth and shedding speeds of condensed liquid drop slow down after adding non condensate gas, which leads to the generation of relatively large liquid drop. The liquid drop holds up the steam heat transfer and the non condensate gas suppresses the steam condensation. A thorough understanding of the non condensate gas hold up mechanism on steam heat transfer could provide certain guidance for the steam heat transfer enhancing and steam heat utilization improvement.