A series of experiments was carried out to study the matching relationship between the pore structure in the reservoir and the molecular radius of gyration. The hydrodynamic radius Dh (molecular coil dimension) was tested by dynamic light scattering and was be used to characterize the crimping degree of polymer chains and molecular coil dimension. The storage modulus and loss modulus were studied through creep recovery. CT scan was used to measure the parameters of pore throat structure in the reservoir. Finally, a polymer injection experiment has been carried out to evaluate the adaptability of polymer molecular coil dimension in the pore structure of the reservoir. Comparing pore radius with the molecular radius of gyration, it was shown that the storage modulus ratio is the key critical factor of oil displacement efficiency and its value is in the range of 10-20. It was also shown that the optimal stable pressure gradient is in the range of 0.05-0.3 MPa/s; a medium stable pressure gradient of 0.3-0.6 MPa/s is acceptable; and a stable pressure gradient above 0.6 MPa/s or no stable pressure gradient is poor. Greater molecular weight and higher concentration of polymer in the core with low permeability do not provide stable pressure.

中文翻译：

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聚合物分子线圈尺寸在储层孔隙结构中的适应性

开展了一系列实验研究储层孔隙结构与分子回转半径的匹配关系。流体动力学半径Dh（分子线圈尺寸）通过动态光散射测试，用于表征聚合物链的卷曲度和分子线圈尺寸。通过蠕变恢复研究了储能模量和损耗模量。CT扫描用于测量储层孔喉结构参数。最后，通过注聚合物实验，评价聚合物分子线圈尺寸对储层孔隙结构的适应性。比较孔隙半径与分子回转半径，结果表明，储能模量比是驱油效率的关键关键因素，其取值范围为10-20。还表明，最佳稳定压力梯度在 0.05-0.3 MPa/s 范围内；0.3-0.6 MPa/s的中等稳定压力梯度是可以接受的；0.6 MPa/s以上的稳定压力梯度或无稳定压力梯度为差。具有低渗透率的岩心中较大的分子量和较高的聚合物浓度不能提供稳定的压力。