中文摘要：

用与低渗透储集层孔喉尺度相近的微管模拟储集层微小孔喉,以流体在微管中的流动特征为研究对象,采用微尺度方法研究低渗透储集层非线性渗流规律。对半径分别为10.0μm、7.5μm、5.0μm和2.5μm的熔融石英微管中去离子水的流动特征进行实验研究,分析了4种尺寸微管中去离子水的平均流速与压力梯度的关系、压力梯度对流体边界层的影响以及流动阻力系数与雷诺数的关系。研究结果表明：微管中流体的低速流动具有非线性特征,且随着微管半径的减小,流动的非线性程度增强,可以用二次函数对非线性流动特征进行拟合;微流动中,有效流体边界层厚度占微管管径的比例随压力梯度的增大而降低;雷诺数可作为非线性流动的判据,雷诺数小于10-3的低速流动具有非线性特征。

英文摘要：

Take the flow characteristics of fluid in micro tube as the object,the characteristics of nonlinear filtration in low permeability reservoirs were studied using micro scale method by simulating the micro pore throat of reservoir with the micro tube which has the similar scale pore throat of low permeability reservoirs.The flow characteristics of de-ionized water flowing through fused silica capillary tubes with radius of 10.0 μm,7.5 μm,5.0 μm and 2.5 μm were investigated in experiments.Relationship between average flow rate and pressure gradient,effect of pressure gradient on fluid boundary layer,and relationships between flow resistance coefficient and Reynolds number were analyzed respectively in these experiments with different micro tubes.The flow of fluid through micro tubes with low velocity has nonlinearity,and the extent of nonlinearity increases with the tube radius decreasing.Nonlinear flow experimental points can be matched by quadratic curve.In micro flow,the percentage of effective fluid boundary layer thickness to micro tube radius decreases with the pressure gradient increasing.Research results indicated that Reynolds number can be used as the criteria of nonlinear flow.Flows with Reynolds number less than 10-3 have nonlinear features.