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特超稠油的胶体化学性质研究
Study on the Colloid Properties of Super-heavy Oil
【作者】 侯珍珍;
【导师】 杨国华;
【作者基本信息】 中国石油大学 , 化学工程与技术, 2010, 硕士
【摘要】 随着中轻质原油可利用量的逐渐减少,稠油在我国石油行业中所占的比例越来越大。黏度大于100000mPa·s的特超稠油是稠油中黏度更高、密度更大、沥青质胶质含量更高的部分,是稠油中最典型的代表。但由于其黏度过高,国内外仅有的少量报道集中于其开采驱替,对其从化学本质的角度进行的研究鲜有报道,对这类稠油胶体体系的胶体化学性质进行研究,进而指导解决其开采加工过程中遇到的难题显得日益重要。论文以稠油的胶体结构理论为基础,选用8种稠油(特超稠油)为研究对象,关联其宏观物性和微观性质,实现了对稠油的微观性质、胶体性质、宏观物性系统地综合研究,在此基础上研究添加剂等处理前后体系物理化学性质的变化,掌握其变化规律及作用机理。对特超稠油微观性质的研究包括组分组成、性质和平均结构的研究。利用分子量、介电常数和折光率数据计算平均偶极矩,得到四组分的极性变化规律,并研究了各组分分子的元素组成和结构。结果表明,沥青质的高极性是由其高芳烃含量、高杂原子和金属含量引起的,这是研究稠油其它性质的基础。黏度是反映稠油流变性能的基本参数,胶体稳定性是研究胶体分散体系的基础。用Brookfield布氏数字流变仪和质量分率电导率法分别考察了特超稠油的黏温性质和胶体稳定性,并从组分组成和组分性质的角度分析了其影响因素。研究表明,组分组成及含量对稠油的黏度具有决定作用,高分子量的胶质沥青质组分的含量之和越大,体系黏度越大;组分间的相互作用是形成稳定胶体体系的重要原因,胶质沥青质的含量之比越大、相容匹配性越好,体系胶体稳定性越高。添加剂、高温蒸汽及二氧化碳处理是稠油降黏的有效手段,研究了添加剂等处理前后特超稠油黏度、黏温性质和胶体稳定性的变化规律。采用红外光谱、同步荧光光谱及激光粒度分析等表征手段研究了添加剂对沥青质的作用机理。结果显示添加剂处理后的沥青质红外及荧光光谱图和粒度均有不同变化,说明添加剂对沥青质的作用存在且有一定的强度,粒度变化说明添加剂可以改变沥青质的缔合程度。此外,高温蒸汽可能通过使沥青质发生烷基侧链断裂反应降低沥青质含量而CO2通过溶解作用改变胶团结构来实现降黏作用。
【Abstract】 Heavy crude oil will cover a larger proportion of petroleum trade in our country with the consuming of light crude oil. The super-heavy crude oil with viscosity above 100000 mPa·s is the most typical one. No mature study methord has been developed home and abord because of its higher viscosity, bigger density and higher content of resin and asphaltene. Most of the study are about its displacement mechanism.Study of its colloid properties for such kind of reservoirs are in urgent need in order to find reasonable producing and fining technology.In this paper,based on the colloidal structures theories of heavy crude,the microscopic nature, colloidal properties and the macroscopic properties of the eight Super-heavy oil samples were studied systematicly and comprehensively, and the relationship among them were explored.On this basis, the effect of additives on the viscosity, or physical and chemical properties of the super-heavy oil were studied.The macroscopic properties of heavy oil includ the fraction composition, properties and mean structures of fractions.The mean dipole moment values of fractions were computed from the data of molecular weight, dielectric constant and refractive index. On this basis, the element composition and mean structure were also studied. The results showed that the aromatic ratio, heteroatom and metal contents contribute to the high polarity of the asphaltenes. This is the basis of other properties of heavy oil.Viscosity is the basic parameters reflecting the rheological properties, and colloidal stability is the basis of colloidal dispersion. The Brookfield rotary viscometer was used to measure the rheological properties, and Mass Fraction Normalized Conductivity method was used to study the colloidal stability of samples. The fraction composition and properties of fractions were studied to explore the factors impacting the viscosity-temperature properties and colloid stability. It can be concluded that the fraction characteristics and content paly the decisive role in the viscosity and colloidal stability of super-heavy oil. The samples with greater heavy components have greater viscosity value, and the samples with high contents ratio and high properties Intermateability of resins and asphaltenes have the greater value of colloidal stability. Additives, high temperature steam and CO2 are effective methods to reduce the viscosity. The viscosity property and colloidal stability variation of samples with or without additive were studied. Fourier transform infra-red spectrometer, the synchronous fluorescence spectumeter and the Zetasizer Nano ZS particle size analyzer were used to analyse the effect of addictives on the asphaltenes. The results showed that the effect of addictives on the asphaltenes is strong and the reduce of the viscosity is achieved by the changing of the asphaltenes’particle size. In addition, the viscosity-reducing effect of high temperature steam and CO2 is achieved by breaking asphaltenes’alkyl-side-chain and by changing micellar structure.
【Key words】 Super-heavy oil; Dipole moment; Viscosity; Colloidal stability;
- 【网络出版投稿人】 中国石油大学 【网络出版年期】2011年 04期
- 【分类号】TE345
- 【被引频次】7
- 【下载频次】724