稠油火驱二次点火主控因素及点火策略

为了实现火驱开发过程中熄火油层再次燃烧,保障火驱开发效果,通过一系列室内物理模拟实验和油藏数值模拟计算,开展包括点火温度、通风强度、地下含油饱和度分布、结焦带等影响二次点火的主控因素的研究,给出了合理的二次点火温度和通风强度的范围,同时结合注气井地下空气腔规模给出了不同条件下启动油层二次燃烧的点火策略.结果表明,电点火温度应控制在450 ℃以上,点火期间通风强度应维持在10 m³/(m²·h)以上,对于需要注燃料油进行二次点火的注气井,燃料油的用量不低于已燃区空气腔体积的2/7.

Main controlling factors of re-ignition and ignition strategies in heavy oil fire flooding

In order to realize the re-ignition of the extinguished oil layer in the process of fire flooding development and ensure the fire flooding effect, such main controlling factors of re-ignition as the ignition temperature, air flux, underground oil saturation distribution in oil layer and coking zone were investigated with a series of indoor physical simulation experiments and numerical simulation calculation of oil reservoir. In addition, the reasonable ranges of ignition temperature and air flux were provided. At the same time, in combination with the scale of the underground air chamber of gas-injection well, the re-ignition strategy of the oil layer under different conditions was given. The results show that the electrical ignition temperature should be controlled at higher than 450 ℃, and the air flux should be maintained at more than 10 m³/(m²·h). Furthermore, for the gas-injection wells which need to be injected with fuel oil for re-ignition, the amount of fuel oil should be not less than 2/7 of the air chamber volume in the burned area.