Abstract: Based on different proportions of CO2 and CH4 mixture gas source, the experiment pretreated Changqing oil by using selfmade saturated dissolved gas crude oil processing device under simulated stratum conditions, and then saturated dissolved gas crude oil was got through step by step depressurizing under gathering and transportation conditions (0~3.5 MPa). Crude oil's solubility (Rs), volume factor (Bo), condensation point (TZ), viscosity (μ) and yield value (τy) were studied by using highpressure equipment, which could measure properties of live oil, and highpressure rheometer. The results showed that Rs and Bo increased with the increase of pressure. As the temperature increased, Rs decreased and Bo increased. When experiments were conducted with the same temperature and pressure, Rs (CO2) was the double of Rs(CH4), and the Rs of mixture gas was between the two formers, and the crude oil got better expansion effect with the mixture gas. Among mixture gas, molar ratio of 9∶1 (n(CO2)/n(CH4)) had the best expansion effect, and such mixture gas had best improvement of crude oil's condensation point, viscosity and yield value.

Key words: Carbon dioxide,    ,  Methane,    ,  Solubility,   ,  Rheological properties

摘要： 以CO₂、CH₄ 混合气为气源,在地层条件下利用自主研制的饱和溶气原油装置对长庆原油进行预处理,通过逐级降压得到地面集输工况(0~3.5MPa)下的饱和溶气原油。通过溶气原油物性测试装置与高压流变仪分析了气体组成、温度、压力等对饱和溶气原油溶解度Rs、体积系数Bo、凝点TZ、黏度μ 和屈服值τy 的影响规律, 并讨论混合气稀释效应与溶胀效应对长庆原油的影响。结果表明,随着压力升高,Rs、Bo 升高,随着温度降低,Rs 升高,Bo 降低;相同温度、压力下,Rs(CO₂)约为Rs(CH₄ )的2倍,但CH4 的溶解明显促进了CO₂对长庆原油的溶胀效果;n(CO₂)/n(CH₄ )=9∶1混合气对长庆原油的溶胀作用最佳,且对长庆原油凝点、黏度和屈服值的改善效果最优。

关键词: CO₂,    ,  甲烷,    ,  溶气特性,    , 流变特性