原油乳化液高效破乳技术的相关机理与特性研究

发布时间：2018-01-20 02:01

本文关键词： 原油乳化液电场波形小型快速测评装置静电聚结微观机理　出处：《北京石油化工学院》2015年硕士论文　论文类型：学位论文

【摘要】：高含水油田、深水油田、边际油田和绿色油田的开发给油气集输流程带来新的挑战,对高效紧凑型原油电脱水技术的需求日益迫切,不仅需要相关原油电脱水技术和设备创新,原油乳化液电脱水过程中水滴的微观静电聚结机理研究也有待深入。本文以原油乳化液为研究对象,以介观和微观为研究尺度,以对比工频和高频电场为切入点,围绕原油乳化液高效破乳技术的相关机理与特性开展了一系列的实验研究。本文首先在介观尺度下借助静电聚结实验装置研究了静态环境下原油乳化液在不同电场波形下的静电聚结特性,实验结果表明在原油乳化液特性一致、其余电场参数相同的条件下,不同波形破乳效果的排序依次为:交流方波?交流正弦波?交流三角形波?脉冲直流。搭建了小型原油静电聚结快速测试评价试验装置,运用流花11-1油田老化油进行动态静电聚结脱水实验研究,结果表明老化油在高频/高压电场下破乳效果最高可达97.8%,明显高于工频/高压电场4.2%的聚结脱水效果。在微观尺度上,运用“近红外相机+显微镜”组合,研究了原油乳化液中单个水滴在不同电场参数和物性参数下的破碎机理,实验结果表明,工频电场主要通过对液滴的过度拉伸使液滴破碎,且液滴失稳时的最大长径比可达2.54;高频电场则通过增加液滴界面膜的不稳定性导致液滴扭曲破碎,失稳时的最大长径比低于工频电场。以两个液滴和液滴群为研究对象,观察了电场强度、电场频率和液滴粒径值对静电聚结过程中液滴中心距和相对运动速度的影响,实验结果表明,频率主要影响液滴接触碰撞时的瞬间行为影响聚结,电场强度对液滴聚结速度的影响较大,但电场强度过大会引起液滴发生电分散现象,导致多个更细碎液滴分散在乳化液中,增加了乳化液的稳定性,液滴粒径越大聚结速度越快,但液滴粒径较大时,电场频率和电场电压值均不宜过高,此时液滴界面膜不稳定,外界扰动剧烈时液滴容易发生破碎。论文的研究成果丰富了原油乳化液静电聚结破乳的研究内涵,揭示了高频/高压交流脉冲电场在破乳聚结方面有别于其他电场的深层作用机制及其优越性,为该项电场破乳技术在原油脱水(盐)领域的应用提供了技术依据,为油气集输工艺的高效紧凑化开发奠定了坚实的基础。
[Abstract]:The development of high water cut oil field, deep water field, marginal oil field and green oil field brings new challenges to oil and gas gathering and transportation process, and the demand of high efficiency compact electric dehydration technology for crude oil is more and more urgent. It is necessary not only to innovate the technology and equipment of electric dehydration of crude oil, but also to study the micro-electrostatic coalescence mechanism of water droplets in the process of electric dehydration of crude oil emulsion. Mesoscopic and microcosmic as the research scale, contrast power frequency and high frequency electric field as the breakthrough point. A series of experimental studies have been carried out on the mechanism and characteristics of high efficiency demulsification technology for crude oil emulsions. Firstly, the electrostatic coalescence experimental device at mesoscopic scale was used to study crude oil emulsions under different electrical conditions in static environment. Electrostatic coalescence characteristics under field waveform. The experimental results show that the order of demulsification effect of different waveforms is as follows: ac square wave when the characteristics of crude oil emulsion are the same and the other electric field parameters are the same. Ac sine wave? Ac triangular waves? Pulse DC. Set up a small test device for rapid test and evaluation of electrostatic coalescence of crude oil, and use aging oil of Liuhua 11-1 oil field to carry out dynamic electrostatic coalescence dehydration experimental study. The results show that the highest demulsification effect of aging oil under high frequency / high voltage field is 97. 8, which is obviously higher than that of coalescence and dehydration of power frequency / high voltage electric field 4.2%. The crusher mechanism of single water droplet in crude oil emulsion under different electric and physical parameters was studied by using the combination of "near infrared camera microscope". The experimental results show that. The power frequency electric field mainly makes the droplet break up by excessive drawing, and the maximum aspect ratio can reach 2.54 when the droplet is unstable. The high frequency electric field increases the instability of the liquid droplet interfacial film and results in the distortion and breakage of the droplet, and the maximum aspect ratio is lower than the power frequency electric field. The electric field intensity is observed with two droplets and droplet groups as the research objects. The effect of electric field frequency and droplet particle size on the droplet center distance and relative velocity during electrostatic coalescence. The experimental results show that the frequency mainly affects the instantaneous behavior of droplet contact and collision. The electric field intensity has a great influence on the droplet coalescence speed, but if the electric field intensity is too high, the droplet will be dispersed in the emulsion, which will increase the stability of the emulsion. The larger the droplet size is, the faster the coalescence speed is, but when the droplet size is larger, the electric field frequency and electric field voltage should not be too high, and the liquid drop boundary film is unstable. The research results of this paper enrich the research connotation of electrostatic coalescence and demulsification of crude oil emulsion. The deep action mechanism and superiority of high frequency / high voltage AC pulse electric field in demulsification and coalescence are revealed. It provides the technical basis for the application of the electric field demulsification technology in the field of crude oil dehydration (salt) and lays a solid foundation for the highly efficient and compact development of oil and gas gathering and transportation technology.
【学位授予单位】：北京石油化工学院
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TE868

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