重质油组分分子结构与粘温性能的关系

发布时间：2018-07-11 15:14

  本文选题：重油 + 结构解析　； 参考：《中国石油大学(华东)》2015年硕士论文

【摘要】：目前,世界轻质原油的可供利用量正在减少,而重质原油在全球资源量中的比例呈逐年增加之势。重质油的高粘度、大型聚合体结构使其在开采和输送等方面受到制约,这直接影响了重质油输送的成本和效益。因此,有必要找出影响重油粘度的重要因素。重质油的分子结构是极其复杂的,且重油分子结构对其物理化学性质有着重大的影响,为预测重油的理化性质和化学反应特性,需要对重油分子结构进行具体且详尽的分析。然而,重油是由相对分子质量较大、结构复杂的化合物所组成的混合物,对于这样的物质,难以用一个准确的化合物来表示,可以考虑用Cn Hm的平均分子式来表示。在本课题中,对六种重质原油的性质进行分析,对每个油样进行六组分的分析。根据每一个组分的分子量、元素分析、核磁共振等数据,根据改进的B-L法,计算出原油各组分的结构参数,解析出其可能的分子结构。由于每一个组分可能有多个平均分子结构,采用分子力学的方法,找出能量最低、结构最稳定的结构作为最后确定的结构,其中,组分越重,分子结构越复杂,而重胶质的结构甚至比单元沥青质的单元片层的结构更为复杂。对各组分进行动力学计算,结果表明,组分越重,密度及粘度的值也随之增加。各组分的分子结构建立之后,按照重油真实的比例,建立了不同重油的周期型结构模型。计算不同温度下的粘度,并与实验值作对比。计算得到的粘度比实验值偏大,可能是系统误差偏大以及粘度计算方法上仍存在不足之处,但是趋势和实验结果是一致的。影响重油粘度的因素有很多,且影响程度不一样,本课题中,采用灰熵分析的方法,得出这样的结果,原油组成对其粘度的影响程度的顺序依次为:胶质≈沥青质NiN≈芳香分SVFe。因此,研究胶质、沥青质的分子结构的特征对重油的开采、加工及运输有重要的意义。
[Abstract]:At present, the available amount of light crude oil in the world is decreasing, while the proportion of heavy crude oil in global resources is increasing year by year. The high viscosity of heavy oil and the structure of large polymer restrict the exploitation and transportation of heavy oil, which directly affect the cost and benefit of heavy oil transportation. Therefore, it is necessary to find out the important factors affecting the viscosity of heavy oil. The molecular structure of heavy oil is extremely complex, and the molecular structure of heavy oil has a great influence on its physical and chemical properties. In order to predict the physicochemical and chemical properties of heavy oil, it is necessary to analyze the molecular structure of heavy oil in detail. However, heavy oil is a mixture of compounds with relatively large molecular weight and complex structure. It is difficult to express such a substance by an accurate compound, and can be expressed by the average molecular formula of CN Hm. In this paper, the properties of six kinds of heavy crude oil are analyzed, and the six components of each oil sample are analyzed. According to the data of molecular weight, element analysis and nuclear magnetic resonance of each component, the structural parameters of each component of crude oil were calculated according to the improved B-L method, and the possible molecular structure of each component was analyzed. Since each component may have more than one average molecular structure, the lowest energy and most stable structure can be found by molecular mechanics, in which the heavier the component, the more complex the molecular structure is. The structure of heavy resin is more complex than that of unit asphaltene. The kinetic calculation of each component shows that the heavier the component is, the higher the density and viscosity are. After the molecular structure of each component was established, the periodic structure model of different heavy oil was established according to the true proportion of heavy oil. The viscosity at different temperatures was calculated and compared with the experimental values. The calculated viscosity is larger than the experimental value, which may be due to the large system error and the shortcomings in the method of viscosity calculation, but the trend is consistent with the experimental results. There are many factors that affect the viscosity of heavy oil, and the degree of influence is different. In this paper, the method of grey entropy analysis is used to get the result that the order of influence of crude oil composition on viscosity is: colloid 鈮，

本文编号：2115623