针对低渗透油藏储集层孔道微细、孔隙结构复杂等特点,采用管径为20、15、10μm的微圆管,以纳微米聚合物颗粒溶液为流动介质,研究微圆管中流体微观流动规律,分析纳微米聚合物颗粒溶液的实验流速与压力梯度的关系,研究纳微米聚合物颗粒溶液在窄小孔道中微尺度效应下的微观流动规律,明确在微管内所受微观力和流体动力学特性。研究表明:随着微管内径的逐渐减小,纳微米聚合物溶液的流速均明显减小;随着纳微米聚合物颗粒尺寸和溶液质量浓度的增加,流体流速逐渐降低;实验压力范围内,纳微米聚合物流速与压力梯度基本呈线性关系;微管管径越小,颗粒粒径越大,非达西流动特征越显著。
In view of the narrow pore and throat and complex pore structure characteristics of low permeability reservoir, one-dimensional microtubes with inner diameters of 20, 15 and 10 μm are used to study the dynamic mechanism of fluid flow in microtubes. The relationship between flow velocity and pressure gradient are analyzed using nano-micron polymer as mobile media. Meanwhile, the flow mechanism of polymer nano-micron under microscale effect in the narrow throats are investigated, and the micro force and dynamic characteristic in the microtubes are revealed. The research shows that with the decrease of the microtube diameter, or the increase of nano- polymer particle size and solution concentration, the fluid flow velocity will decrease. The flow velocity of fluid in the microtube is propotional to the pressure gradient, but the nonlinear fluid flow characteristic will gradually stand up with the decrease of microtube diameter or the increase of nano-polymer particle size.