驱油用纳米二氧化硅的制备及改性研究

发布时间：2018-05-20 09:42

本文选题：纳米二氧化硅 + 硅烷偶联剂　；参考：《中国石油大学(华东)》2015年硕士论文

【摘要】：纳米液驱油是一种新兴的采油技术,它以水溶液为传递介质,在水中形成几百个纳米小颗粒,具有很大的比表面积和表面能,使得原油易于剥落成小油滴,而被驱替液驱替出来。另一方面,纳米液的颗粒能暂时堵塞孔道,扩大波及体积,使未被波及到的原油驱替出来。其中,纳米SiO_2驱油剂因具有良好的剪切增稠触变性,同时在减压增注、封堵孔道方面表现出优异的性能而受到广泛关注,然而其油容性差,降低油水界面张力幅度小,且能吸附在岩石表面影响岩石的润湿性,因此需进行表面修饰改变其性能。本文分别用长链型硅烷偶联剂及非离子-阴离子型烷氧基硅烷偶联剂改性纳米SiO_2,使产物能够调控润湿性,降低油水界面张力,提高洗油效率。并得出以下结论:(1)通过硅氢加成反应合成了一种新型非离子-阴离子型烷氧基硅烷偶联剂,转化率可达91.3%,具有良好的表面活性,可用于纳米SiO_2改性以提高表面活性,表面张力可降低至33.8 mN·m-1,对应的CMC为10.96×10-3 g·mL-1,且随着分子量的增大,临界表面张力γcmc增大,临界胶束浓度CMC降低。(2)纳米SiO_2改性产物能成功调控润湿性,改性剂疏水链越长,弱亲水基团越多,产物疏水性越强。且改性产物的润湿性主要受改性浓度调控,改性浓度越大,润湿性变化越明显。(3)纳米SiO_2改性产物表现出优异的界面活性,其中由AEPH300与Si(CH3CH2O)3H硅氢加成反应所得产物改性的纳米SiO_2降低油水界面张力能力最强,低至9.0 mN·m-1,而未改性的纳米SiO_2仅为17.4 mNm·-1。(4)在洗油实验中,由AEPH300与Si(CH3CH2O)3H硅氢加成反应所得产物改性的纳米SiO_2洗油效果最好,且非离子-阴离子型烷氧基硅烷偶联剂改性纳米SiO_2的洗油效果整体优于长链烷基硅烷偶联剂。总之,改性纳米SiO_2溶液是一种高效驱油剂,其润湿性可由接枝基团的种类、数目、链长、浓度调控,油水界面张力可低至9.0 mN·m-1,具备良好的洗油性能。
[Abstract]:Nano-liquid flooding is a new oil recovery technology. It takes aqueous solution as transport medium and forms hundreds of small nanoparticles in water. It has a very large specific surface area and surface energy, which makes crude oil easy to peel into small oil droplets. And the displacing fluid came out. On the other hand, the nanoparticles can temporarily block the pore channel and expand the sweep volume, so that the unaffected crude oil can be driven out. Among them, nanometer SiO_2 flooding agent has attracted wide attention because of its good shear thickening and thixotropy, at the same time, it has excellent performance in increasing injection pressure and sealing pore channels. However, its oil capacity is poor and the amplitude of oil-water interfacial tension is reduced. And adsorption on the rock surface affects the wettability of rock, so surface modification is needed to change its performance. In this paper, nano-SiO2 was modified with long chain silane coupling agent and non-ionic anionic alkoxy silane coupling agent, respectively, which made the product adjust wettability, reduce oil-water interfacial tension and improve oil washing efficiency. The following conclusions are drawn as follows: (1) A new nonionic anion alkoxy silane coupling agent was synthesized by hydrosilylation reaction. The conversion of alkoxy silane can reach 91.3%, and it has good surface activity. It can be used in the modification of nanometer SiO_2 to improve its surface activity. The surface tension can be reduced to 33.8 mm ~ (-1) and the corresponding CMC is 10.96 脳 10 ~ (-3) g mL ~ (-1). With the increase of molecular weight, the critical surface tension 纬 cmc increases, and the critical micelle concentration (CMC) decreases. The more weak hydrophilic groups, the stronger the hydrophobicity of the products. The wettability of the modified product is mainly regulated by the modified concentration. The higher the modified concentration, the more obvious the wettability change is. The nanometer SiO_2 modified by AEPH300 and Si(CH3CH2O)3H hydrosilylation reaction has the strongest ability to reduce the interfacial tension of oil and water, as low as 9.0 mn m-1, while the unmodified nano-SiO_2 is only 17.4 mNm -1.14) in the oil washing experiment. The oil washing effect of nanometer SiO_2 modified by hydrosilylation reaction of AEPH300 and Si(CH3CH2O)3H was the best, and the washing effect of Nonionic alkoxy silane coupling agent modified nano SiO_2 was better than that of long chain alkyl silane coupling agent. In a word, the modified nanometer SiO_2 solution is a kind of high efficiency oil displacement agent. Its wettability can be controlled by the type, number, chain length, concentration of grafted groups, and the interfacial tension of oil and water can be as low as 9.0 mn m -1, which has good oil washing performance.
【学位授予单位】：中国石油大学(华东)
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TQ127.2;TE39

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