Huang Xiaohe, Wang Yuyi, Long Yunqian, Liu Jing, Zheng Han, Nie Wen, Han Hongyan
School of Petrochemical Engineering & Environment, Zhejiang Ocean University, Zhoushan 316022, China.
United National-Local Engineering Laboratory of Harbor Oil & Gas Storage and Transportation Technology, Zhejiang Ocean University, Zhoushan 316022, China.
Polymers (Basel). 2022 Apr 28;14(9):1803. doi: 10.3390/polym14091803.
The nanoparticles dispersion system has complex migration characteristics and percolation law in porous media due to the interaction between the nanoparticles and porous media. In this paper, lab experiments were carried out to characterize the morphology, particle size distributions, and apparent viscosities of SiO/P(MBAAm--AM) polymeric nanoparticle solution, investigate its migration characteristics in porous media, and probe its capability of enhanced oil recovery (EOR) in the reservoirs. Quartz microtubule, sand pack, and etched glass micromodels were used as the porous media in the flow and flooding experiments. Gray image-processing technology was applied to achieve oil saturation at different flooding stages in the micromodel for calculating the EOR of the SiO/P(MBAAm--AM) polymeric nanoparticle solution. The results show that The SiO/P(MBAAm--AM) polymeric nanoparticles are spherical with diameters ranging from 260 to 300 nm, and the thicknesses of the polymeric layers are in the range of 30-50 nm. As the swelling time increases from 24 to 120 h, the medium sizes of the SiO/P(MBAAm--AM) polymeric nanoparticles increase from 584.45 to 1142.61 nm. The flow of the SiO/P(MBAAm--AM) polymeric nanoparticles has obvious nonlinear characteristics and a prominent scale effect at a low-pressure gradient, and there should be an optimal matching relationship between its injection mass concentration and the channel size. The flow tests in the sand packs demonstrate that the SiO/P(MBAAm--AM) polymeric nanoparticles can form effective plugging in the main flow channels at different permeability areas and can break through at the throat to fulfill the step-by-step profile control. Moreover, the profile control of the SiO/P(MBAAm--AM) polymeric nanoparticles strengthens with an increase in their swelling time. The microscopic flooding experiment in the etched glass micromodel confirms that the SiO/P(MBAAm--AM) polymeric nanoparticles can block dynamically and alternatively the channels of different sizes with the form of loose or dense networks to adjust the fluid flow diversion, improve the sweep efficiency, and recover more residual oil. The SiO/P(MBAAm--AM) polymeric nanoparticles can achieve an enhanced oil recovery of 20.71% in the micromodel.
由于纳米颗粒与多孔介质之间的相互作用，纳米颗粒分散体系在多孔介质中具有复杂的运移特性和渗流规律。本文通过室内实验，对SiO/P(MBAAm-AM)聚合物纳米颗粒溶液的形态、粒径分布和表观粘度进行了表征，研究了其在多孔介质中的运移特性，并探讨了其在油藏中的提高采收率(EOR)能力。在流动和驱替实验中，采用石英微管、填砂模型和蚀刻玻璃微模型作为多孔介质。应用灰度图像处理技术，获取微模型中不同驱替阶段的含油饱和度，计算SiO/P(MBAAm-AM)聚合物纳米颗粒溶液的采收率。结果表明，SiO/P(MBAAm-AM)聚合物纳米颗粒呈球形，直径在260300nm之间，聚合物层厚度在3050nm之间。随着溶胀时间从24h增加到120h，SiO/P(MBAAm-AM)聚合物纳米颗粒的中值粒径从584.45nm增加到1142.61nm。SiO/P(MBAAm-AM)聚合物纳米颗粒在低压梯度下的流动具有明显的非线性特征和显著的尺度效应，其注入质量浓度与孔道尺寸之间应存在最佳匹配关系。填砂模型流动实验表明，SiO/P(MBAAm-AM)聚合物纳米颗粒在不同渗透率区域的主流道中能形成有效封堵，并能在喉道处突破，实现逐步调剖。此外，SiO/P(MBAAm-AM)聚合物纳米颗粒的调剖效果随溶胀时间的增加而增强。蚀刻玻璃微模型中的微观驱替实验证实，SiO/P(MBAAm-AM)聚合物纳米颗粒能够以松散或致密网络的形式动态交替地封堵不同尺寸的孔道，调节流体流动转向，提高波及效率，采出更多的剩余油。SiO/P(MBAAm-AM)聚合物纳米颗粒在微模型中可实现20.71%的采收率提高。
