Abstract: On the basis of component change of carbon in oil,interfacial tension between oil and carbon dioxide and the quality of supercritical carbon dioxide of Yushulin oil fields in Daqing area,the formation change of carbon dioxide miscible oil displacement was simulated.The model of carbon dioxide miscible flooding in these oil fields was established,and the equation of carbon dioxide miscible flooding was found.Some new and important mechanisms on the craft mode of carbon dioxide miscible flooding and the water-gas alternating injection were determined.The supercritical carbon dioxide could lower the tension of the interface of involved oil and water,and the content of carbon dioxide in carbon component of oil could reach the highest value in the miscible region.The effect of water on the carbon dioxide miscible flooding is unfavorable for the alternating injection of water and carbon dioxide.

Key words: supercritical carbon dioxide, miscible flooding, microcosmic mechanism, oil component, interfacial tension, mathematical model

摘要： 根据大庆榆树林油田原油组分变化、CO₂与原油界面张力关系及CO₂超临界性质,对CO₂混相驱地层情况进行了模拟研究,建立了CO₂混相驱驱替模型和方程。研究结果表明,超临界状态的CO₂可以降低所波及油水的界面张力;混相时混相带原油含碳组分中C₂₀以下的含量达到了最高值;水气交替注入时,水对混相有不利的影响。

关键词: 超临界二氧化碳, 混相驱, 微观机理, 原油组分, 界面张力, 数学模型