聚醚类二氧化碳增稠剂材料的设计、合成与性能研究

发布时间：2019-06-19 08:34

【摘要】：提高石油采收率是增强我国资源保障能力、提高我国能源安全水平、更好地满足社会经济发展需要的迫切要求。经过多年的发展,CO_2驱油已经成为最具潜力的三次采油技术之一。但是在CO_2驱油过程中,由于CO_2流体粘度太低导致CO_2倾向于向采油井发生“指进”而没有更多的接触油藏中的原油导致波及效率不高,限制了CO_2的驱替效率。增加CO_2流体粘度可以降低CO_2-原油流度比,削弱甚至消除粘性指进现象,进而改善CO_2驱替效率。因此研究出一种能够增加CO_2粘度提高采收率的增稠剂材料对石油开采具有深远的影响。含氟聚合物以及在大量助溶剂条件下的聚硅氧烷是最有效的、能够显著增稠CO_2的两类CO_2增稠剂,遗憾的是这两类聚合物因环境和成本问题限制了其实际应用,其他聚合物因在CO_2中溶解度低而不能有效增稠CO_2。本论文旨在设计并合成低成本、环境友好的可溶于CO_2并能够有效增稠CO_2的非氟聚合物,为CO_2增稠剂材料的实际应用提供理论和技术支持。本论文首先以聚醚中CO_2溶解性最好的聚环氧丙烷(PPO)为亲CO_2基础聚合物,通过共聚向PPO中引入增稠基团并研究其增稠CO_2的性能;在实现增稠CO_2后,从热力学出发分析并研究了聚醚的改性方法,将硅结构单元引入到聚醚主链结构中提高了材料在CO_2中溶解性;最后对提高了CO_2亲和性的改性聚醚进行进一步的增稠改性,从而达到更好的CO_2增稠效果。首次以亲CO_2的环氧丙烷齐聚物(PPO)为基础聚合物,以苯基为增稠基团,设计并合成了环氧丙烷-苯基缩水甘油醚共聚物和环氧丙烷-氧化苯乙烯共聚物作为CO_2增稠剂。为了促进聚合物溶解于CO_2,我们用亲CO_2的乙酸酯基取代了厌CO_2的羟基。通过浊点压力测试系统研究了聚醚增稠剂在CO_2中的相行为,为了键联结构与溶解性关系,我们研究了苯基对聚合物物化性质的影响。在实现溶解的基础上,研究了增稠基团含量、spacer、聚合物分子量对增稠剂增稠CO_2效果的影响。实验表明我们设计的两种聚醚共聚物对CO_2都有一定的增稠效果。CO_2增稠剂研制的难点在于CO_2是一种弱溶剂,通常高分子量材料在CO_2中溶解度低,限制了CO_2增稠剂的发展。在确定了聚醚共聚物能够增稠CO_2之后,为了改善聚醚在CO_2中的溶解性进而为增稠改性提供更好的溶解基础,我们从热力学出发分析并讨论了聚醚的改性方法。限制聚醚在CO_2中溶解性的主要因素在于不利的混合焓,预期降低聚醚分子间作用力能够提高聚醚的溶解性;我们将硅结构单元引入聚醚分子结构中,设计并合成了硅改性聚醚;表面张力和玻璃化转变温度测试表明硅结构单元能够显著降低聚醚分子间相互作用并提高聚醚链柔性,有利于改善混合焓和混合熵;硅改性聚醚在CO_2中的相行为测试表明硅结构单元能够显著提高聚合物在CO_2中的溶解性。综合分析之后我们认为硅改性聚醚在CO_2中具有较高的溶解性主要归因于硅结构单元降低了聚合物分子间作用力。基于上述讨论的聚醚改性方法我们进一步设计合成了硅改性的聚醚增稠剂以期望获得更好的增稠效果。我们用大体积七甲基三硅氧烷作为侧基改性聚醚,预期能够在降低聚醚分子间作用力的同时增大聚合物的自由基体,提高链柔性,增加聚醚在CO_2中的溶解。由于环氧丙烷-苯基缩水甘油醚共聚物和环氧丙烷-氧化苯乙烯共聚物都能够有效增稠CO_2,我们继续选择苯基作为增稠基团引入到亲CO_2的硅改性聚醚中。首先设计并合成了七甲基三硅氧烷改性聚醚增稠剂;其次研究了七甲基三硅氧烷对增稠剂分子间作用力和链柔性的影响;然后研究了硅改性聚醚增稠剂在CO_2中相行为;最后研究了硅改性聚醚对CO_2的增稠效果。粘度测试表明硅改性聚醚增稠剂能够更大程度的增稠CO_2。
[Abstract]:The improvement of oil recovery rate is an urgent need to enhance our country's resource security, improve our energy security and meet the needs of social and economic development. After many years of development, CO _ 2 oil displacement has become one of the most promising three-time oil recovery technology. However, in the process of CO _ 2 oil displacement, since the viscosity of CO _ 2 fluid is too low, CO _ 2 tends to generate "finger-in" to the production well, and no more of the crude oil in the contact reservoir results in a high impact efficiency, and the displacement efficiency of the CO _ 2 is limited. The increase of CO _ 2 fluid viscosity can decrease the ratio of CO _ 2 to crude oil, weaken or even eliminate the viscous fingering phenomenon, and improve the efficiency of CO _ 2 displacement. Therefore, a kind of thickening agent material which can increase the CO _ 2 viscosity and improve the recovery ratio has a far-reaching influence on the oil exploitation. the fluorine-containing polymer and the polysiloxane under the condition of a large amount of co-solvent are the most effective and can obviously thicken the two types of CO _ 2 thickening agents of the CO _ 2, and unfortunately, the two types of polymers limit the practical application of the two types of CO _ 2 thickeners due to environmental and cost problems, Other polymers are not effective in thickening CO _ 2 due to the low solubility in CO _ 2. The purpose of this paper is to design and synthesize a low-cost, environment-friendly non-fluorine polymer which is soluble in CO _ 2 and can effectively thicken the CO _ 2, and provides theoretical and technical support for the practical application of the CO _ 2 thickener material. Polypropylene oxide (PPO) with the best solubility of CO _ 2 in the polyether is firstly used as the base polymer of the pro-CO _ 2, the thickening group is introduced into the PPO by the copolymerization, and the performance of the thickening CO _ 2 is studied; after the thickening of the CO _ 2, the modification method of the polyether is analyzed and studied from the thermodynamics, The introduction of the silicon structural unit into the polyether main chain structure improves the solubility of the material in the CO _ 2; and finally, the modified polyether with the improved CO _ 2 affinity is further thickened and modified so as to achieve better CO _ 2 thickening effect. The propylene oxide-phenyl glycidyl ether copolymer and the propylene oxide-oxide-styrene copolymer were designed and synthesized by using the propylene oxide oligomer (PPO) of the pro-CO _ 2 as the base polymer for the first time, and the propylene oxide-phenyl glycidyl ether copolymer and the propylene oxide-oxidized styrene copolymer were designed and synthesized as the CO _ 2 thickening agent. In order to promote the dissolution of the polymer in CO _ 2, we replace the hydroxyl of the anaerobic CO _ 2 with the acetate group of the pro-CO2. The phase behavior of polyether thickener in CO _ 2 was studied by cloud point pressure test system, and the effect of phenyl on the physical and chemical properties of polymer was studied in order to bond the structure and solubility. The effect of thickening group content, spacer and polymer molecular weight on the thickening of CO _ 2 was studied on the basis of the dissolution. The results show that the two kinds of polyether copolymers have a certain thickening effect on CO _ 2. The difficulty in the development of CO _ 2 thickener is that CO _ 2 is a weak solvent, the solubility of high molecular weight materials in CO _ 2 is low, and the development of CO _ 2 thickener is limited. In order to improve the solubility of the polyether in the CO _ 2 and to provide a better dissolution basis for thickening modification after the determination of the ability of the polyether copolymer to thicken the CO _ 2, the modification method of the polyether is analyzed and discussed from the thermodynamics. The main factors that limit the solubility of polyether in CO _ 2 are the unfavorable mixing ratio, which is expected to lower the solubility of polyether, and we introduce the silicon structural unit into the molecular structure of the polyether, and design and synthesize the silicon modified polyether. The results of surface tension and glass transition temperature show that the silicon structural unit can significantly reduce the interaction between the polyether molecules and increase the flexibility of the polyether chain, which is beneficial to the improvement of the mixing and mixing entropy; The phase behavior of the silicon modified polyether in CO _ 2 shows that the silicon structural unit can significantly improve the solubility of the polymer in the CO _ 2. After the comprehensive analysis, we think that the high solubility of the silicon modified polyether in the CO _ 2 is mainly attributed to the reduction of the intermolecular force between the polymer molecules. Based on the above-discussed polyether modification method, we further developed a silicon-modified polyether thickener to achieve a better thickening effect. We use the large volume of heptamethyl trisiloxane as the side group modified polyether, and it is expected that the free base of the polymer can be increased while the action force between the polyether molecules is reduced, the flexibility of the chain is improved, and the dissolution of the polyether in the CO _ 2 is increased. Since the propylene oxide-phenyl glycidyl ether copolymer and the propylene oxide-oxide-styrene copolymer are capable of effectively thickening the CO _ 2, we continue to select the phenyl group as the thickening group to be introduced into the silicon-modified polyether of the pro-CO2. Seven-methyl trisiloxane modified polyether thickeners were first designed and synthesized; secondly, the effect of the heptamethyltrisiloxane on the intermolecular force and the chain flexibility of the thickener was studied, and then the phase behavior of the silicon modified polyether thickener in the CO _ 2 was studied. The effect of silicon modified polyether on the thickening of CO _ 2 was studied. The viscosity tests show that the silicon modified polyether thickener can thicken the CO _ 2 to a greater extent.
【学位授予单位】：吉林大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：TE39

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