非活塞驱替条件下粘性指进的表征及影响因素

Characteristics of viscous fingering and influencing factors under the conditions of non-piston displacement

建立低压力梯度条件下驱油的数学模型,对其进行求解,对比指进和非指进情况下油藏的饱和度,重点分析了驱替液粘度和原油粘度对粘性指进的影响,并且研究了CO2驱油机理与指进的关系。结果表明:驱替液粘度越高,指进程度越轻;原油粘度越高,指进程度越严重。在高压情况下,CO2能够有效地减缓指进程度。

A mathematical model of oil displacement under the condition of low pressure gradient has been established and solved. Reservoir saturations are compared for the circumstances of fingering and non-fingering. The effects of displacing fluid viscosity and crude oil viscosity on viscous fingering are specially analyzed. The relationship between CO2 flooding mechanism and fingering is discussed. The result shows that the higher the viscosity of displacing fluid is,the smaller the fingering is; and the higher the oil viscosity is,the larger the fingering is. CO2 can effectively mitigate fingering under high pressure.