火烧油层驱油特征的参数敏感性分析

在火烧油层驱油机理的基础上，依据油气层渗流理论，燃烧理论，建立了火烧油层驱油数学模型。用数值解法对干式和湿式两种燃烧进行了比较，得出：湿式燃烧比干式燃烧的驱油效果好。针对湿式燃烧的特点，对火烧油层驱油过程中的参数进行了敏感性分析，取得了有关结论即1）蒸汽带驱油是火烧油层过程中的一个重要机理；2）随着湿式燃烧水气比的增加，发生氧化反应的区域长度扩大，蒸汽带的温度下降，对流前缘速度增加，加速了热对流的传导，驱油效率增大；3）在湿式燃烧过程中，随着氧气利用率的降低，发生氧化反应的区域长度扩大，蒸汽带的温度下降，燃烧1立方米油砂所需空气量增加，燃烧前缘速度减少，驱油效率几乎不变；4）在湿式燃烧过程中，随着注入空气量的增加，发生氧化反应的区域长度扩大，蒸汽带的温度升高，燃烧前缘速度增加，对流前缘速度增加，加速了热对流的传导，驱油效率增大。

The Sensitivity Analysis of Parameters for In Situ Combustion

According to hydrocarbon reservoir percolation theory an d combustion theory, and on base of oil displacement mechanism of in-situ comb ustion, the mathematical modeling is set up. The dry combustion is compared wi th the wet one by using the numerical method. The conclusion is drawn that the e ffect of the wet combustion is better than that of the dry one. In view of the c haracteristics of the wet combustion, through the analysis sensitivity of the co rresponding parameters, the relevant conclusions are drawn: (1)the steam zone oi l displacement is an important mechanism in the process of in-situ combustion; (2)with water-gas ratio increase, the region of oxidation reaction expands. The n the temperature of zone oil becomes low and the velocity of convective front i ncreases. So it accelerates the conduction of heat convection and enhances oil d isplacement efficiency; (3) with oxygen utilization decrease, the region of oxi dation reaction expands, the temperature of zone oil becomes low, the air quanti ty needed for burning one cube of oil sand increases and the velocity of convect ive front decreases. As a result, oil displacement efficiency almost keep consta nt; (4) with the amount of injection air increase, the region of oxidation react ion expands, the temperature of zone oil rises, the velocity of combustion front increases and the velocity of convective front increases. So it accelerates th e conduction of heat convection and enhances oil displacement efficiency.