聚表剂耗散颗粒动力学模拟及溶液特性研究

Dissipative particle dynamics simulation and study on solution properties of polymer surfactants

为了提高高矿化度非均质稠油油藏的采收率,基于耗散颗粒动力学(DPD)模拟,对聚合物表面活性剂KL-6的溶液特性进行了研究,分析了KL-6的分子结构及水溶液增黏机理,并与部分水解聚丙烯酰胺(HPAM)进行了对比。利用DPD方法模拟了PAM、HPAM、KL-6在水溶液中的溶解状态,研究了分子链结构对聚合物分子行为的影响,分析了不同浓度HPAM和KL-6溶液的增黏性;比较了HPAM和KL-6溶液的增黏性、表面活性、抗盐性及两种聚合物溶液的微观结构。结果表明,聚表剂KL-6具有分子间缔合作用和表面活性,其临界缔合浓度为0.6 g/L;在临界缔合浓度以上,KL-6溶液黏度显著高于HPAM;在相同浓度下,KL-6溶液的表/界面活性显著高于HPAM;盐溶液中KL-6分子链形成了三维网状结构,具有很好的抗盐能力。研究结果可为开发和应用性能优异的聚合物表面活性剂提供理论指导。

To enhance oil recovery of high-salinity and heterogeneous heavy oil reservoirs, dissipative particle dynamics (DPD) simulations have been performed to determine the properties of KL-6 polymer surfactant solution, molecular structure and viscosity-enhancement mechanism of KL-6 have been analyzed, and comparison has been made with partially hydrolyzed polyacrylamide (HPAM).Based on DPD simulation, conditions of PAM, HPAM, KL-6 in water have been determined to highlight the impact of molecular chain structures on properties of polymer molecules, viscosity-enhancement capacities of HPAM and KL-6 solutions at different concentrationshave been analyzed to compare microscopic structures, viscosity-enhancement capacities, surface activity and salinity-resistance of these HPAM and KL-6 polymer solutions. Research results show that KL-6 has both intermolecular association and surface activity with a critical association concentration of 0.6 g/L; at an association concentration higher than the critical, KL-6 solution has viscosity significantly higher than that of HPAM; at the same concentration, KL-6solution has surface activity much more than that of HPAM; with molecular chains to form 3D network structures in salt solution, KL-6 displays outstanding salinity resistance. Relevant research results may provide theoretical basis for development and application of desirable polymer surfactants.