【作者】 李春秀；

【导师】 李英；

【作者基本信息】 山东大学 ， 物理化学， 2013， 硕士

【摘要】 水基泡沫不仅在许多传统领域(如矿物浮选,洗涤,三次采油等)中应用广泛,近年来在其它领域(如光电阻隔,红外消光,电磁干扰屏蔽,爆炸缓解以及作为纳米材料的合成模板等)中也有重要的应用,其重大的应用前景使相关理论的研究和技术开发备受重视。伴随着与泡沫相关的新技术的产生和发展,如何开发满足越来越苛刻的实际应用条件要求的泡沫体系,已经成为亟待解决的难题。比如泡沫应用于极端苛刻条件油藏来提高采收率,为高温高盐油藏、稠油油藏、低渗透油藏等难动用油藏的有效开发揭示了良好前景。另外,当前采用烟道气捕集二氧化碳以及使用捕集后剩余复合气体作为驱油泡沫的发泡气体,由于其在节能减排保护环境方面的重要意义引人瞩目。在这些应用技术中,高温高盐、油相存在以及复合气体作为发泡气体,都是对泡沫性能具有重大挑战的苛刻条件,本文通过分别考察在上述苛刻条件下的泡沫性能,并探究相关机理,取得的理论认识用于指导应用体系的开发和工艺改进,为泡沫的有效应用奠定基础。本论文主要分为四个部分：第一部分为高温高盐条件下表面活性剂稳定的水基泡沫稳定性及机理研究。采用泡沫衰减法测定泡沫半衰期,对比了高温情况下不同表面活性剂溶液产生的泡沫其稳定性受盐度的影响。实验结果表明,一种极性基间柔性连接的双亲水基表面活性剂脂肪醇聚氧乙烯醚硫酸钠AES,在镁离子存在下形成的泡沫具有超高稳定性,远远高于其他表面活性剂。采用平面液膜稳定性、红外光谱等实验研究与分子模拟相结合的方法,以十二烷基硫酸钠SDS为对比体系,深入探讨了钙镁离子对表面活性剂分子界面行为及泡沫液膜稳定性的影响,给出了镁离子存在下AES超稳泡沫的机理,指出了一条高温高盐条件下取得超高泡沫稳定性的新技术途径。第二部分中,考察了高温高盐条件下表面活性剂复配体系的泡沫稳定性,通过探讨高盐情况下泡沫稳定性受温度的影响规律,得到了在超高矿化度条件下具有良好泡沫稳定性的体系,并采用分子模拟方法研究了高盐条件下复配表面活性剂在气液界面的相互作用机理,提出了采用表面活性剂复配协同优化泡沫稳定性的微观规律。第三部分主要研究油相对发泡能力和泡沫稳定性的影响。考察了原油以及其他油相的消泡能力,利用自行设计的微流控装置考察乳状液滴与泡沫气泡的相互作用,并采用分子模拟探讨表面活性剂在油水和气液界面的吸附排布行为,通过实验和分子模拟结果相结合的方法,提出了油相的消泡机制,并探讨了低张力泡沫用于驱油的可行性。论文最后一部分研究了不同发泡气体对泡沫稳定性的影响,并探讨了相关机理。主要涉及的气体为氮气、二氧化碳气体以及工厂烟道废气在碳捕集后产生的复合气体。通过对比不同气体为发泡气体的情况下泡沫的生成能力、泡沫稳定性的变化,给出了工厂废气作为发泡气体用于油田驱油的可能性。更多还原

【Abstract】 Theoretical research and technology development about foam have attracted a lot attention for their important potential application, because aqueous foam has got successful utilization, not only in traditional regions, such as mineral floatation, detergent, and enhanced oil recovery, but also in many other advance fields recently, such as photoelectric barrier, infrared extinction or electromagnetic interference shielding, blast mitigation, and being used as soft bionic template for controllable synthesis of functional nanoparticles, etc. With the generation and quick development of the new technologies of foam, it has been imminent and urgent to develop the preferable foam systems meeting the requirement of more and more harsh conditions in the practical applications. For example, foam flooding can be applied to the reservoir with harsh conditions in enhance oil recovery, which provides promising prospects for the effective development of the high temperature and salinity reservoirs, heavy oil reservoirs and low permeability reservoirs, where crude oil is hard to be displaced. Besides, the using of carbon dioxide (CO2)and complex gases gotten from the flue gas as the foaming gas has been paid much attention, as it is very valuable because of its energy conservation and emissions reduction. However, the poor foam stability under harsh conditions, such as high temperature, high salinity, the existence of crude oil and using CO2as the foaming gas, has always been a problem.In this paper, foam stability under harsh conditions (high salinity, high temperature, the existence of oil and CO2being the foaming gas) was discussed and the mechanisms were studied to guide the development of application system and improve the process.This paper is divided into four parts:In the first part, the stability of foam stabilized by single surfactant at high salinity and high temperature was investigated. And the ultra stable aqueous foam stabilized by a kind of flexible connecting bipolar-headed surfactant alkyl polyoxyethylene sulfate (AE3S) with Mg2+coexisting was reported. Detailed molecular behavior of AE3S in foam film with divalent cationic Ca2+or Mg2+coexisting was investigated by molecular dynamic simulation, foam lamella stability evaluation and Infrared spectroscopy, comparing with traditional surfactant sodium dodecyl sulfate SDS, for the purpose of finding out how the micro character and array behavior of molecules in the foam film determined by molecular interaction effect the formation of Newton black film (NBF), and revealing the key mechanism maintaining ultra high foam film stability.The second part focuses on the mixed surfactants under various temperature and salinity. Optimized foam formulations for different application conditions were gotten. Mechanism of the enhanced foam stability by the synergism of AES and DSB was studied by molecular dynamics simulation, and the microscopic law to optimize foam stability by the surfactant synergism was proposed.In the third part, defoaming and antifoaming behaviors of the crude oil and several other kinds of oil were investigated. Microfiuidic device was designed to study the interaction between foam bubbles and emulsified oil droplets. Defoam and antifoam mechanisms were investigated by combining results of experimental and molecular dynamics simulation methods. And the feasibility of the application of low tension foam flooding on the oil displacement was discussed.Finally, the influences of foaming gas (nitrogen, composite gas and carbon dioxide) on the foamability and foam stability have been studied. The reasons for the instability of CO2foam were studied, and relatively stable CO2foam stabilized by SDS was found. Effluences of salinity, pH and surfactant concentration on CO? foam stability were studied. And the application probability of flue gas on the oil displacement was discussed.更多还原