考虑应力敏感和启动压力梯度的低渗透油藏数值模拟研究

利用应力敏感实验得到了低渗透油藏残余渗透率表达式；理论推导了考虑动态渗透率变化的启动压力梯度表达式，在此基础上，提出拟动力函数的概念得到了应力敏感和启动压力综合作用下的油水相渗曲线。然后利用Eclipse软件，通过引入ROCKTABH和Threshold Pressure关键字实现了考虑启动压力和应力敏感效应的低渗透油藏数值模拟研究方法。研究结果表明：考虑启动压力和应力敏感效应后，由于油相流动能力变差，水相渗流能力相对增强，残余油饱和度升高的影响，注采井间压力梯度较大，含油饱和度下降较慢，无水采收期较短，含水率上升速度较快，最终采收率较低。

Numerical Reservoir Simulation Considering Threshold Pressure Gradient and Stress Sensitive Phenomenon

The remaining permeability coefficient of stress sensitive rock is derived. Also the function between the threshold pressure gradient and pressure difference is obtained. Then the oil water relative permeability curve considering the stress sensitive phenomenon is perceived. After all these are completed, the numerical simulation considering stress sensitive phenomenon in low permeability reservoir is tried. Keywords such as ROCKTABH and Threshold Pressure are applied in order to take features of stress sensitive and threshold pressure gradient into consideration. The results prove that after stress sensitive and threshold pressure gradient are considered, the oil phase becomes harder to move while relatively the water becomes easier to move. The pressure gradient between the injection well and the production well is bigger, and the oil saturation decreases slowly. The water-free production period is shorted with a bigger increased rate of water cut and finally a smaller oil recovery rate is achieved.