【作者】 邢士理；

【导师】 郭旭虹；

【作者基本信息】 华东理工大学 ， 化学工艺， 2011， 硕士

【摘要】 蜡和沥青质是原油中的重要组分,其在原油中的含量和状态决定着原油流动性能。当原油中蜡含量或者沥青质含量较高时,原油的开采和输送均非常困难。因此,研究制备高效的流动改性剂以解决高蜡、高沥青原油的开采和运输中的难题,具有重要的经济价值和社会意义。本文采用基团修饰法合成了两个系列的梳型马来酸酐-α-烯烃共聚物,其中胺化改性的梳型共聚物对高蜡原油降凝,酯化改性的梳型共聚物对高沥青原油降粘作用明显。为了简化研究对象,模拟原油组成,配制了模型油,分别对模型油和原油的降凝、降粘机理进行了深入研究。主要工作如下：(一)通过十八胺胺化修饰马来酸酐-α-烯烃共聚物侧链,并通过改变十八胺的与马来酸酐的投料比例,合成了一系列疏水基团与亲水基团比例不同的梳型共聚物(MAC)。采用核磁共振氢谱(1H NMR)分析了MAC的基团比例,热重分析(TGA)测定了MAC的耐热温度,凝胶渗透色谱(GPC)测定了MAC的分子量；采用流变学、偏光显微镜(PLM)、差示扫描量热法(DSC)、X射线衍射法(XRD)研究了MAC与模型油的作用机理。研究发现：MAC可以与模型油中的蜡组分相互作用,形成共晶,减小蜡晶的尺寸并大幅度提高其分散性,从而显著降低模型油的凝点和屈服应力。此外,以辽河油田高蜡原油为例,测试了MAC对高蜡原油的降凝效果。在添加量为0.1 wt%和50℃下,MAC可使原油的屈服应力降低92%,凝点降低约10℃左右,0℃下的显微镜照片显示原油中蜡晶尺寸明显降低,也验证了上述结果。(二)通过聚乙二醇200酯化修饰马来酸酐-α-烯烃共聚物侧链得到梳型共聚物(PMAC)。采用核磁共振氢谱(1H NMR)证实了PEG成功接枝到马来酸酐-α-烯烃共聚物上,热重分析(TGA)测定了PMAC的耐热温度,凝胶渗透色谱(GPC)测定了PMAC的分子量。从辽河油田高稠油中提取了沥青质,并配制了不同沥青质含量模型油。首先研究了沥青质与原油中蜡组分的相互作用。其次,研究了PMAC与模型油的作用效果。从偏光显微镜照片结果可以看出PMAC可以分散团聚在一起的沥青质,从而降低高沥青模型油的屈服应力。最后,以辽河油田超稠原油为例,测试了PMAC的降粘效果。在20℃下和添加量为0.3 wt%时,PMAC可以使原油的零切粘度降低98%左右,并且随着添加量的增加,粘度进一步的降低。但是,降凝、降粘剂的加剂量与降凝、降粘效果不是线性的,当添加剂量达到某一临界值后,添加剂分子与原油中绝大部分的蜡共结晶或者吸附于蜡晶表面,会形成相对稳定的晶体结构,与沥青质等极性组分的相互作用也达到相互稳定的状态,降凝、降粘剂的作用接近其极限,再加大剂量其作用效果不再会明显提高,而且使成本增加。另外,偏光显微镜照片也显示出原油中的蜡晶尺寸减小并且被分散开。综上所述,本文成功的合成了两种系列的梳型共聚物,分别应用于解决目前原油开采和输送过程中出现的凝点高和粘度大等问题,并且根据实验结果提出了梳型共聚物的降凝、降粘机理如下：十八胺修饰的梳型共聚物MAC可以与高蜡原油中的蜡组分形成共晶,为蜡组分的结晶提供晶核并且改变蜡晶形态从而达到降低高蜡原油的凝点和屈服应力的效果；PEG200修饰的梳型共聚物PMAC中的极性基团可以与原油中的沥青质相互作用,从而使沥青质原来的堆砌状态分散开,非极性基团可以与原油中的蜡组分相互作用,从而大幅度的降低原油的粘度和屈服应力。更多还原

【Abstract】 Aiming to solve wax deposition and asphaltenes aggregation problems in crude oil. Two series of comb-type copolymers were synthesized in this thesis. Furthermore, their applicationes as flow improver in the crude oil were also studied in the follow part. Finally, the mechanism of the flow improvement of comb-type copolymers was explored based on the model oil and crude oil. The main work is shown as below:In the first part, maleic anhydride copolymers (MAC) with different ratios of maleic anhydride (MA) to amine were synthesized and the effect of these comb-type copolymers was evaluated by addition in model oil. Amination degree of MAC was determined by 1H NMR, decomposition temperature of MAC was tested by TGA and the molecular of MAC was determined by GPC. And their effects on crystallization of paraffin in waxy oil were characterized by rheometry, polarizing light microscopy, DSC and XRD. According to the results of rheology, it can be concluded that the high degree of amination leads to more hydrophobic alkyl side chain and thus benefit for reducing the size of paraffin crystals. However, higher aminated MAC didn’t have good effects on crude oil. Due to higher degree of amination leads to more hydrophobic groups, the content of hydrophilic groups would be decreased correspondingly. When the crude oil only contained high content of paraffins, the higher aminated MAC would have a good effect on reducing the size of crystals, viscosity, and yield stress. When the crude oil contained high content of paraffins as well as asphaltenes, there would be an optimized ratio of the hydrophobic group to the hydrophilic group in MAC, which has a good effect on reducing the viscosity and yield stress of crude oil.In the second part, the maleic anhydride-a-octadecene copolymer was grafted with the oxyethyl groups by esherification named PMAC which could assemble with the asphaltenes molecules and disperse their aggregation status. The structure of PMAC was tested by 1H NMR, decomposition temperature of PMAC was tested by TGA and the molecular middle product of PMAC was determined by GPC. The effect of PMAC as the asphaltenes dispersant was evaluated by rheology and polarizing microscope (PLM). The experimental results showed that PMAC could well disperse the aggregated asphaltenes. And the dispersed asphaltenes as well as long alkyl chains of PMAC could provide local nucleation sites for waxy crystals which could depresse the size of the wax crystals, therefore, the viscosity of the crude oil was dropped drastically.According to the results of experiment, it is easily conclude that two kinds of comb-type copolymers which could be used to depressant the pour point of wax oil and viscosity of asphaltene oil respectively were synthesized. It is also conclude that MAC and PMAC have a distinct effect on dropping the energy consume in the process of oil transportation, therefore, they are excellent candidate for crude oil transportation and extraction.更多还原