不同压力下梳形聚合物结构对油品流动性影响的研究

发布时间：2018-03-10 06:08

本文选题：压力　切入点：高蜡原油　出处：《华东理工大学》2015年硕士论文　论文类型：学位论文

【摘要】：原油中的重质碳氢化合物常在环境温度低于原油的析蜡温度时析出,从而堵塞管道,为原油的开采和运输带来严重的困难。向原油中加入聚合物降凝剂改善原油的低温流动性是一种经济有效并被广泛采用的方法。然而,目前的研究普遍在常压下进行,而原油常常储存在压力很高的地层深处,在运输过程当中输油管道内部也存在着一定的压力。压力对于原油的流动性质有着不可忽略的影响。因此,有必要在高压条件下系统的研究原油的流动特性以及聚合物降凝剂的降凝效果。本文通过自由基聚合和侧链接枝的方法,制备了两类基于马来酸酐-α-烯烃共聚物的聚合物降凝剂,一种是含有脂肪侧链的MAC-24-18与MAC-18-18系列共聚物,另一种是具有芳香侧链AMAC.NMAC和ANMAC系列共聚物。通过核磁共振氢谱(1H-NMR)对聚合物的结构进行了分析。在常压下,运用流变仪、荧光显微镜等测量仪器探究了聚合物中烷基链长度和侧链芳香度对油品流动性及蜡结晶过程的影响。结果显示所合成的梳型共聚物均能够有效的降低含蜡模型油的屈服值,并对蜡晶的形貌或分散性起到一定的改善作用。通过荧光显微镜观测含蜡模型油中的蜡晶形貌以及聚合物分布后发现聚合物的侧链基团种类对蜡结晶过程有很大影响,不含芳环的聚合物(MAC系列)主要通过共晶的方式改变了蜡晶的形貌,而含有芳环的聚合物(AMAC、NMAC和ANMAC系列)则主要通过吸附及排斥机理起到分散蜡晶的作用。利用高压流变仪,考察了含蜡原油在不同静压力下流变性质的变化。压力的升高可以显著提高含蜡原油的粘度,同时通过促进原油中石蜡的结晶过程使得原油拥有更高的析蜡点和屈服应力。考察了芳香性和非芳香性共聚物在高压下对原油屈服值的降低效果,发现这两类聚合物在常压和高压下对含蜡油的改善效果有着不同的趋势。接枝有芳香性聚合物的添加剂在常压下可以显著的降低含蜡原油的屈服应力,然而在高压下其降低原油屈服应力的效果则增长缓慢,而MAC系列共聚物则在高压和常压下均能够与原油中的蜡进行共晶从而起到很好的效果。
[Abstract]:Heavy hydrocarbons in crude oil are often released when the ambient temperature is lower than the wax precipitation temperature of the crude oil, thereby blocking the pipeline. It is an economical, effective and widely used method to improve the low temperature fluidity of crude oil by adding polymer depressant to crude oil. However, the current research is generally carried out under normal pressure. The crude oil is often stored in the depths of high pressure, and there is a certain pressure inside the pipeline during the transportation process. The pressure has an important effect on the fluidity of crude oil. It is necessary to systematically study the flow characteristics of crude oil and the depressant effect of polymer depressant under high pressure. Two kinds of polymer depressants based on maleic anhydride-伪-olefin copolymers were prepared. One was a series of MAC-24-18 and MAC-18-18 copolymers containing fat side chains. The other is the aromatic side chain AMAC.NMAC and ANMAC series copolymers. The structure of the polymer was analyzed by 1H-NMRs. The effects of alkyl chain length and side chain aromaticity on oil fluidity and wax crystallization were investigated by fluorescence microscopy. The results showed that the comb-type copolymers could effectively reduce the yield value of waxy model oil. The morphology of wax crystal and the distribution of polymer in waxy model oil were observed by fluorescence microscope, and it was found that the type of side chain group had great influence on the process of wax crystallization. The morphology of wax crystal is changed mainly by eutectic method, while the morphology of wax crystal is mainly changed by means of eutectic method, while the polymer AMA Con NMAC and ANMAC series containing aromatic ring play the role of dispersing wax crystal mainly through the mechanism of adsorption and repellent. The rheological properties of waxy crude oil under different static pressures were investigated. At the same time, by promoting the crystallization process of paraffin in crude oil, the crude oil has higher waxing point and yield stress. The effect of aromatic and non-aromatic copolymers on reducing yield value of crude oil under high pressure is investigated. It is found that the effect of these two kinds of polymers on waxy oil is different under atmospheric pressure and high pressure. The additive grafted with aromatic polymer can significantly reduce the yield stress of waxy crude oil under normal pressure. However, the effect of reducing the yield stress of crude oil at high pressure increases slowly, while the MAC series copolymers can eutectic with the wax in crude oil at high pressure and atmospheric pressure.
【学位授予单位】：华东理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：O631.1;TE39

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