SiO2纳米流体在低渗透油藏中的驱油性能 和注入参数优化*

Flooding Performance and Optimization of Injection Parameters of SiO2 Nanofluid in Low Permeability Reservoirs

尚丹森 侯吉瑞 程婷婷

SHANG Dansen HOU Jirui CHENG Tingting

为研究纳米流体在低渗油藏中的驱油性能，采用实验室自主研发的具有一定疏水性的SiO2纳米颗粒，研究 了SiO2纳米流体的稳定性及其对界面张力的影响，并通过低渗岩心驱替实验评价了SiO2纳米流体的驱油性能， 优化了该纳米流体的注入参数。研究结果表明，纳米SiO2颗粒的粒径中值约为50 nm；纳米SiO2颗粒加量为 0.15%时，界面张力最低，为0.55 mN/m；纳米SiO2颗粒加量在0.15%以下时体系具有较好的稳定性，浓度越高，体 系稳定性越差。岩心驱替实验表明，在渗透率20×10-3 μm2的低渗岩心中，SiO2纳米流体可以有效降低含水率，降 低注入压力，最佳的注入参数为：注入速率0.1 mL/min、注入量0.5 PV、加量0.15%，在此条件下可提高采收率 25.41%。SiO2纳米流体可用于低渗透油藏提高采收率。所合成的具有一定疏水性的SiO2纳米颗粒可用于低渗 透油藏高效提高采收率。图8参22

To investigate the flooding performance of SiO2 nanofluid in low permeability reservoirs，the self-developed modified hydrophobic nanosilica was used to study the stability of SiO2 nanofluid and its effect on interfacial tension. Series of flooding experiments in low permeability cores were conducted to evaluate the performance of SiO2 nanofluid and to optimize the injection parameters. The results showed that the average size of SiO2 nanoparticles was about 50 nm；when the particle concentration was 0.15%，the interfacial tension value was the lowest，being of 0.55 mN/m；when the concentration was below 0.15%，the stability of the system was good，and the higher the concentration，the worse the stability of the system. Flooding experiments in cores with 20×10-3 μm2 showed that SiO2 nanofluid could effectively reduce water cut and injection pressure. The injection parameters reached its optimization when the injection rate，injection volume and particle concentration was 0.1 mL/min，0.5 PV and 0.15% ， respectively. Under these conditions，oil recovery could be enhanced by 25.41%. The SiO2 nanoparticles with hydrophobicity synthesized in this study can be used to efficiently enhance oil recovery in low permeability reservoirs.

10.19346/j.cnki.1000-4092.2021.01.025