Wang Qiuxia, Zhang Wei, Wang Cheng, Han Xiaodong, Wang Hongyu, Zhang Hua
China National Offshore Oil Corporation China Ltd, Tianjin Branch, Tianjin 300459, China.
ACS Omega. 2023 Mar 16;8(12):10980-10990. doi: 10.1021/acsomega.2c07713. eCollection 2023 Mar 28.
The composition of heavy oil is complex, and it is difficult to develop the heavy oil due to its high viscosity and poor fluidity. Therefore, it is very important to clarify the viscous mechanism of heavy oil. In this paper, typical ordinary heavy oil, extra heavy oil, and super heavy oil samples were selected to study the microstructure of heavy oil components and the mechanism of influence on viscosity of heavy oil. The molecular weight, element composition, and polarity of each SARA (short for Saturates, Aromatics, Resins and Asphaltene) component of heavy oil samples were measured and analyzed. The viscosity of heavy oil increases with the increase of the aggregate contents of resins and asphaltene. Resins and asphaltene in heavy oil have a high polarity, high heteroatomic content, and complex molecular structure, which are the key factors affecting the viscosity of heavy oil. On the basis of the experimental results, through simulation calculation and modeling, the microstructure and molecular formula of each component of different heavy oils are obtained, which provides a quantitative reference for revealing the viscosity mechanism of heavy oil. There is little difference in the elemental composition of resins and asphaltene, but the structure is very different and the difference in structure is the key factor leading to the difference in the properties of resins and asphaltene. The content and structure of resins and asphaltene in heavy oil are the key factors leading to the big difference in viscosity of heavy oils.
稠油成分复杂，因其高粘度和差流动性而难以开发。因此，阐明稠油的粘性机理非常重要。本文选取典型的普通稠油、特稠油和超稠油样品，研究稠油组分的微观结构及其对稠油粘度的影响机制。对稠油样品各SARA（饱和烃、芳烃、胶质和沥青质的缩写）组分的分子量、元素组成和极性进行了测定和分析。稠油粘度随胶质和沥青质聚集含量的增加而增大。稠油中的胶质和沥青质具有高极性、高杂原子含量和复杂的分子结构，是影响稠油粘度的关键因素。基于实验结果，通过模拟计算和建模，得到了不同稠油各组分的微观结构和分子式，为揭示稠油粘度机理提供了定量参考。胶质和沥青质的元素组成差异不大，但结构差异很大，结构差异是导致胶质和沥青质性质差异的关键因素。稠油中胶质和沥青质的含量和结构是导致稠油粘度差异巨大的关键因素。
