低渗透油层非线性渗流特征

方法 根据物理模型实验资料，推导出低渗透油层的渗流数学方程，研究了低渗透油层中油、水渗流特征及规律。目的 改善低渗透油层开发效果。结果 启动压力梯度与渗透率成反比；与原油极限剪切应力成正比。当存在启动压力梯度时，渗透率越小，单井产量减小幅度越大；原油的极限剪切应力和井距越大，单井产量减小辐度越大。结论 可以采用整体压裂改造、降低原油剪切应力、小井距及较大生产产压差，改善低渗透油层开发效果。

Nonlinear percolation feature in low permeability reservoir

Method According to experimental data of physical model, this paper derives mathematical equation of percolation for low permeability reservoir, and studies the percolation feature and regularity of oil and water. Purpose To improve the development result of low permeability reservoir. Result The starting pressure gradient has a indirect relationship to permeability, has a direct relationship to ultimatc shear stress of crude oil. When starting pressure gradient exists, the lower the permeability is, the greater the decrease of single well output;the greater the ultimate shear stress and the longer the well spacing are,the greater the decrease of single well output. Conclusion The development result of low permeability reservoir can be improved by monoblock fracturing, lowering shear stress of crude oil, and adopting short well spacing and greater producing pressure drop.