纳微米聚合物颗粒驱油剂的表征及性能评价

Characterization and performance evaluation for nano/micron-sized polymer particles flooding agent

蒸馏沉淀聚合法制备AM/AA/MMA聚合物颗粒,利用傅里叶变换红外光谱仪、扫描电子显微镜和激光粒度仪进行表征,研究Na Cl质量浓度对聚合物颗粒水化膨胀性能的影响及水化时间对聚合物颗粒运移封堵性能的影响,并在不同渗透率的岩心中进行驱油实验。实验结果表明,AM/AA/MMA聚合物颗粒为规则球形,干球粒径约为500 nm。随着水化时间增加,聚合物颗粒粒径逐渐增加,水化时间增至200 h后,粒径基本不再增加。随着Na Cl质量浓度增加,聚合物颗粒的膨胀倍数逐渐减小,质量浓度由5 g/L增至20 g/L,膨胀倍数减小了1.01。随着水化时间增加,聚合物颗粒对岩心的封堵作用增强,水化时间由24 h增至120 h,岩心封堵率增大了40.62%。注入0.5倍孔隙体积、质量浓度为1.5 g/L的聚合物颗粒溶液段塞,可平均提高采收率9%以上,随着渗透率增加,提高的采收率逐渐增加,当渗透率大于50×10-3μm2后,提高的采收率基本不变。

AM/AA/MMA nano/micron- sized polymer particles are prepared by distillation precipitation polymerization method and characterized using Fourier transform infrared spectroscopy, scanning electron microscopy and laser particle size instrument. The effect of Na Cl mass concentration on the hydration expansion property of polymer particles and the effect of hydration time on the migration plugging property of polymer particles are investigated. The oil displacement experiments are carried out in different permeability cores. The experimental results show that AM/AA/MMA polymer particles are regular spherical and the dry particle size is about 500 nm. The polymer particle size gradually increases with the increase of hydration time; But after 200 h, the size of the particle is no longer increased. The expansion ratio of polymer particles decreases gradually with the increase of Na Cl mass concentration; when the Na Cl mass concentration increases from 5 g/L to 20 g/L, the expansion ratio is reduced by 1.01. The pugging effect of polymer particles on core may enhance with the increase of hydration time; From 24 h to 120 h, the core plugging rate is increased by 40.62%. The injection of 0.5 times pore volume polymer particles solution with 1.5 g/L mass concentration can increase by an average of more than 9% of the recovery rate. With the increase of permeability, the enhanced oil recovery increases gradually. But the enhanced oil recovery will remain constant when the permeability is higher than 50×10-3μm2.