随着渤海油田开发程度提高,部分轻、中质油田井筒沥青质沉积问题愈发凸显。为形成沥青沉积预判、机理分析、治理防治的一体化技术,通过CII指数法、黏度法、分光光度法等技术手段,分别开展沥青质稳定性预测实验、沥青质絮凝初始点评价实验以及沥青质分散剂优化实验。CII指数法可以实现渤海油田部分区块沥青质稳定性的精准预测;CII指数与油品密度存在一定程度的相关性,当油品密度低于0.87 g/cm3时,蒸馏切割前后的CII指数相对偏差可超10%,且油品密度越低,CII指数的变化程度越大。就沥青质絮凝初始点判断,绥中样品更易发生絮凝,垦利样品体系相对稳定。优选2C-12型分散剂为最佳沥青质分散剂,当加剂浓度为300 mg/L时,分散沥青质作用良好。研究结果对渤海油田井筒沥青质沉积问题的有效防治具有指导意义。

With the development of Bohai Oilfield, the problem of asphaltene deposition in some light and medium oilfields has become more and more prominent. In order to develop an integrated technology of asphalt deposition prediction, mechanism analysis, treatment and prevention, this paper carried out the asphaltene stability prediction experiment, asphaltene flocculation initial point evaluation experiment and asphaltene dispersant optimization experiment through CII index method, viscosity method, spectrophotometry and other technical means. The results show that the CII index method can accurately predict the stability of asphaltenes in some blocks of the Bohai Oilfield. There is a certain degree of correlation between the CII index value and the density of oil products. When the oil density is lower than 0.87 g/cm3, the relative deviation of the CII index before and after distillation and cutting can exceed 10%, and the lower the oil density, the greater the change in the CII index. Judging from the initial point of asphaltene flocculation, the Suizhong sample is more prone to flocculation, and the Kenli sample system is relatively stable. The 2C-12 type dispersant is preferably the best asphaltene dispersant, and when its concentration is 300 mg/L, it can play a good role in dispersing asphaltenes. This study has guiding significance for the effective prevention and control of wellbore asphaltene deposition in Bohai Oilfield.