低渗透地层压力扰动传播规律

Propagation of pressure disturbance in low permeability formation

在低渗透介质中压力扰动传播规律直接反映了井周围储层的动用范围。通过积分方法近似求解含启动压力梯度和动边界的非线性平面径向不稳定渗流数学模型,得到一种新的压力分布规律和动边界传播规律的解析表达式。在启动压力梯度为零的情况下计算井壁压力,并与经典结果及其他5种解式计算结果对比,文中解析表达式计算结果是准确可靠的。

In low permeability medium,the trend of pressure disturbance propagation is a direct reflection of reservoir producing range around a well.A new analytical expression of pressure distribution and moving boundary propagation has been derived by approximate solving the mathematical model of nonlinear radial unstable fluid flow,which involves threshold pressure gradient and moving boundary using integration method.Wellbore pressure is calculated for zero threshold pressure gradient and compared with the classical result and other five calculation results.It shows that the calculation result of the analytical expression presented in this paper is accurate and credible.