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针对海上稠油开采出现的问题,国内发展了注多元热流体吞吐热力采油技术。与蒸汽热力采油相比,多元热流体可以显著降低稠油黏度、增加油层压力,提高开采效率。本文基于实际气体状态方程和混合法则建立注多元热流体内部流动与传热模型,并与注蒸汽井筒流动与传热状态进行对比,详细对比两种热采介质在井筒流动与传热情况。通过研究发现:在井筒注入相同温度与相同注入速率的多元热流体与饱和蒸汽,多元热流体井筒压力和温度下降速度更快,到达井底时压力更大,温度更低,与地层和油层的温差更小,井筒热损失更少,但是热量含量低,油层加热范围小。要想达到与蒸汽一样加热效果,可以增加多元热流体注入速率和注入温度。同时由于CO_2和N_2作用,油层温度分布更加均匀,热量更多,油层加热范围更大,注多元热流体开采效果更好。
In view of the problems of heavy oil recovery at sea, the domestic development of multi-element thermal fluid throughput thermal oil recovery technology. Compared with the steam thermal oil production, the multiple thermal fluid can significantly reduce the viscosity of heavy oil, increase the reservoir pressure and improve the mining efficiency. In this paper, the internal flow and heat transfer model of multi-element thermal fluid injection is established based on the real gas equation and the mixing rule, and compared with the flow and heat transfer state of steam injection wellbore. The flow and heat transfer of the two kinds of thermal recovery media are compared in detail. Through the research, it is found that the pressure and temperature drop of multivariate thermal fluid in wellbore are much faster than those of multivariate heat fluid and saturated steam at the same temperature and same injection rate. When the pressure reaches the bottom of the well, the pressure is higher and the temperature is lower. The temperature difference is smaller, the wellbore heat loss is less, but the heat content is low, and the oil layer has a small heating range. To achieve the same heating effect as steam, multiple hot fluid injection rates and injection temperatures can be increased. At the same time, due to the action of CO_2 and N_2, the temperature distribution of the oil layer is more uniform and the calories are more, and the heating range of the oil layer is larger, and the effect of multivariate thermal fluid injection is better.