Abstract:

During the thermal recovery of steam injection in heavy oil reservoirs, once steam channeling occurs between wells resulting in ineffective steam circulation, which seriously restricts the expansion of steam sweep volume and the improvement of oil recovery. A 2D visualization experimental apparatus was used to research the phenomenon of steam channeling and the distribution characteristics of remaining oil during steam injection in heavy oil reservoirs. Then, the method of numerical simulation was used to research the influence factors of steam channeling between wells. The results showed that steam migration is a process of steam driving condensate water and water driving oil in porous media. Outside the displacement front, the reservoir temperature gradually decreases and the seepage process presents the characteristics of conventional non?piston water flooding. The seepage speed of water is faster than that of crude oil, which results in an obvious inrush phenomenon and a lot of remaining oil on both sides of channeling path. Finally, the plane sweep efficiency in only 43.16% between injector and producer. However, there is amount of residual oil in the swept zone of steam injection. The main influence factors include the relationship between well location and high permeability zone, the plane heterogeneity, the thickness, the oil viscosity, the speed of steam injection, and etc.

Key words: Heavy oil reservoir, Steam injection, Steam channeling, Visualization experiment, Influence factor

摘要：

稠油油藏在注蒸汽热力采油过程中，井间一旦发生汽窜，导致蒸汽无效循环，将严重制约蒸汽波及体积的扩展和原油采收率的提高。用二维可视化实验装置，研究稠油油藏注蒸汽开发过程中的汽窜现象以及剩余油分布特征，再利用数值模拟方法研究井间汽窜的影响因素。结果表明，多孔介质中蒸汽的推进实际为蒸汽驱动冷凝水与变温热水驱动原油的渗流过程；驱动前缘以外，油藏温度逐渐降低，呈现常规非活塞水驱油特征，水的渗流速度快于原油，呈现明显的突进现象，窜流通道两侧留有大量剩余油，注采井间汽窜时的平面波及系数仅为43.16%；而在热波及区域内，存在绕流残余油与角隅滞留油。影响井间汽窜的主控因素包括：井位与高渗带位置关系、平面非均质性、厚度、原油黏度、注汽速度等。

关键词: 稠油油藏, 注蒸汽, 汽窜, 可视化实验, 影响因素