液态二氧化碳对俄罗斯某油藏稠油的膨胀与萃取作用实验

Swelling and extraction test of heavy oil in a Russian reservoir by liquid carbon dioxide

利用俄罗斯某油藏稠油样品,通过实验分析稠油与液态CO_2混合后两者之间的质量传递作用以及混合物中重相(稠油和CO_2的混合物)和轻相(纯CO_2)的特性变化。研究表明,当混合物中CO_2浓度为10%时,稠油基本上不发生膨胀;当混合物中CO_2浓度高于26%时,由于稠油轻质组分的萃取量超过了CO_2在稠油中的饱和量导致重相体积减少,重相黏度呈指数增长,混合物中CO_2的浓度为26%时,有效降低重相黏度的作用最强;重相和轻相密度、体积系数、气体溶解度和闪蒸重相黏度均随着混合物中CO_2浓度的增加而变大;混合物中最佳的CO_2浓度是26%,此时稠油膨胀最大、重相的黏度值最小;混合物中CO_2的浓度为10%~26%时,轻相的体积最小,驱油效果最好。

The mass transfer between heavy oil and liquid carbon dioxide and the changes of the heavy and light phases in the mixture were tested in lab with heavy oil samples from Russia.The experimental results showed that the heavy oil hardly expanded when the concentration of carbon dioxide in the mixture was 10%.When the concentration of carbon dioxide was higher than 26%,the volume of the heavy phase decreased,and the viscosity of the heavy phase increased exponentially as the light components extracted from the heavy oil exceeded the carbon dioxide saturated in the heavy oil.When the concentration of carbon dioxide in the mixture was 26%,the effect of viscosity reducing to the heavy phase was the strongest.The density of the light and heavy phases,volume factor,and solubility of gas and flash viscosity of heavy phase all increased with the rise of carbon dioxide concentration in the mixture.The best concentration of carbon dioxide in the mixture was 26%,when the heavy oil expanded the most and the viscosity of the heavy phase was the lowest.When the concentration of carbon dioxide in the mixture was between 10%and 26%,the volume of the light phase was the smallest and the oil displacement effect was the best.