考虑流固耦合低渗透储层数值模拟研究

Numerical Simulation Study of Fluid-Solid Coupling Flow in Low Permeablable Oil Reservoir

针对低渗透储层的渗流特征,基于流固耦合的基本理论,考虑低渗透油藏渗流时启动压力梯度和低渗储层的流——固耦合特性,将渗流力学与弹塑性力学相结合,建立适合低渗透油藏的流——固耦合渗流数学模型。在油藏岩土应力和应变分析基础上,结合有效应力原理和岩石骨架本构关系,建立了低渗透储层岩层骨架的数学模型,包括孔隙度方程、平衡方程、几何方程、岩石骨架本构关系等。通过考虑流——固耦合数值模拟的计算结果可以看出,低渗透油藏中流——固耦合效应是十分明显的。

By combining elastio-plastie theory and porous flow mechanics,the fluid-solid coupling mathematical model adapted to low permeable oil reservoir is established. The threshold pressure gradient and the fluid-solid coupling feature of low permeable reservoir are considered in the model. Based on the analysis of rock stress and strain,combining effective stress principle and rock matrix constitutive relation,establishing mathematical model of rock matrix in low permeability reservoir including porosity equations,balance equations,geometrical equations and rock matrix constitutive relations,etc. Contrasting to the result calculated by oil black model,the fluid-solid coupling effect is obvious.