空气辅助蒸汽吞吐采油机理

Research on EOR principles of air assisted CSS

采用填砂模型驱替、吞吐实验及油藏数值模拟，研究蒸汽（热水）-空气驱替和空气辅助蒸汽吞吐规律，分析空气辅助蒸汽吞吐的采油机理．结果表明：100℃温度时，注入空气使热水驱的驱油效率降低，热水-空气驱采出稠油的黏度较热水驱采出稠油的升高20．43％；200℃温度时，蒸汽-空气驱与蒸汽驱的开采效果差别不明显，蒸汽一空气驱采出稠油的黏度较蒸汽驱采出稠油的升高10．80％．蒸汽（热水）-空气驱采出稠油的沥青质质量分数高于蒸汽（或热水）驱采出稠油的．蒸汽-空气驱采出气的02体积分数低于3％，CO2体积分数为3％～5％．在蒸汽吞吐过程中，注入空气与稠油反应而被消耗。利用未反应的Nz及生成的CO2等烟气的增压助排、气体降黏、生热、提高热效率和固砂等作用，能够改善蒸汽吞吐开采的效果，与N2辅助蒸汽吞吐增产效果相当，较蒸汽吞吐周期采油量提高20％～30％，吞吐开采轮次越高，增产效果越明显．

Based on the results of experimental and numerical simulation,the performance of steam(hot water)-air flooding and air assisted cyclic steam stimulation are investigated,and the EOR principles of air assisted cyclic steam stimulation are discussed.The results show that,the displacement efficiency of hot water flooding at 100 ℃is decreased when the air is injected,and the recovery efficiency difference between steam-air flooding and steam flooding at 200℃is not evident.The viscosity of recovered heavy oil of 100℃ hot water-air flooding is 20.43% higher than that of hot water flooding,the viscosity of recovered heavy oil of 200 ℃ steam-air flooding is increased 10.80% than that of 200 ℃ steam flooding.The asphaltene content of recovered heavy oil in steam(hot water)-air flooding is higher than that of steam(or hot water)flooding,while the resin content is equivalent.The produced oxygen content in all the experiments are lower than 3%,the content of CO2 is 3% ~5%.The injection of air during the process of steam stimulation has an obvious effect of increasing pressure,the profile modification and stimulation,the effect of increasing pressure and stimulation is equal to that of N2 assisted steam stimulation,the periodic production than the steam huff and puff can improve 20%~30%.The more times of air assisted CSS,the better the recovery efficiency is.