【作者】 张恒； 苑世领；

【Author】 Heng Zhang;Shiling Yuan;Key Lab of Colloid and Interface Chemistry,Shandong University;

【机构】 山东大学胶体与界面化学教育部重点实验室；

【摘要】 目前大部分油田已进入高含水阶段,大量残余油难以被采出。为提高采油效率,近年来提出的预交联凝胶颗粒(preformedparticlegles,PPG)调剖堵水技术被成功应用于现场。预交联凝胶颗粒由部分水解的聚丙酰胺交联而成,其注入井下后发生吸水溶胀,使体积增大到原来的数十倍甚至几百倍,能对窜流孔道实现有效封堵,提高水驱的波及面积,从而有效地提高原油驱替效率。研究PPG在多孔介质中的运移机制以及运移过程中的影响因素在基础研究和技术应用方面都有着重要的意义。我们通过平衡态和非平衡态动力学方法,系统研究了PPG在溶液中的溶胀行为[1]、PPG通过纳米孔道的机制[2,3]、以及纳米孔道的化学结构和组成对PPG运移行为的影响。结果表明:PPG的溶胀主要与其亲水基团的水化能力有关;PPG通过狭窄纳米孔道的能力主要与其骨架的柔性和脱水能力有关,且纳米孔道表面极化出的水化层对其运移也起到润滑作用;纳米孔道表面的化学组成与结构通过影响表面水化层的结构和动力学性质影响PPG的输运。更多还原

【Abstract】 Mass of oil was still left underground after traditional oil production.To increase oil-driving efficiency,a lot of oil displacing agents were designed.Gel treatment has been successfully used to enlarge sweep volume,as the huge water content in oil is becoming a major problem.PPG,short for preformed particle gel,is a super absorbent polymer that recently are widely used in many China oil fields.It was made up by cross-linked partially hydrolyzed polyacrylamide and preformed on ground before injection.When transported to target formation,it can swell up to plug the big channel,then divert injected water into un-swept area.Understanding the translocation mechanism of PPG in porous medium and the factors affect the process is of vital importance for fundamental research and technological application.We have investigated the swelling of PPG and its translocation process in silica nanopores by conducting a series molecular dynamic simulations[1-3].The super absorbent property of PPG was ascribed to the strong hydration ability of its hydrophilic groups.The surface hydration layer induced by surface silanol groups of nanopore was found to promote PPG’s propagation for its screening and lubrication effect.The soft,flexible nature and dehydration ability of PPG makes it translocating through silica nanopores with small openings easily.The nanopore surface chemistry and heterogeneity affects the translocation of confined PPG by affecting the hydration layer indirectly.更多还原