Abstract: Steam-foam coinjection process is applied to improve the sweeping efficiency of conventional steam drive. It promises significant recovery ot oil not recoverable by steam injectionprocess only. In this paper, a mathematical model for steamfoam coinjection processes is presentedand its numerical processing is discussed. All the mechanisms leading to surfactant losses andflow resistance of foam are taken into account. The flow resistance of foam is modelled bychanging the gas phase relative permeability and residual gas saturation in the presence offoam. The flow resistance of foam is affected by those parameters such as surfactant concentration,oil saturation, temperature, permeability,water and gas phase velocity, etc.The results of field simulation showed that the injection of foaming agent will significantly improve sweeping efficiency and oil recovery of steam drive process. The calculatingefficiency of the numerical models on a microcomputer is practical and satisfactory.

Key words: foamer, steam injection, mathematical model, numerical simulation, flow resistance

摘要： 提出了一个注蒸汽加泡沫过程的数学模型并讨论了数值处理方法.模型考虑了泡沫剂损失的各种机理及泡沫的流动阻力.用修改气相相对渗透率和束缚气饱和度的方法描述泡沫的流动阻力.泡沫的流动阻力受泡沫剂浓度、温度、油饱和度、渗透率以及水相和气相达西流速的影响.对一个现场问题的模拟结果表明：在非均质油藏注泡沫可以改善蒸汽的波及体积,提高采收率.

关键词: 泡沫剂, 注蒸汽, 数学模型, 数值模拟, 流动阻力