聚合物溶液及三元复合体系驱替盲端油的微观机理

Microscopic oil displacement mechanism of polymer solution and ASP system in deadend pores.

大庆油田聚合物驱已经开始了大规模的工业化应用 ,三元复合驱的矿场试验也已取得了极大的成功。为进一步推动两种技术的应用和完善 ,充分认识其驱油机理 ,利用微观仿真模型 ,对比研究了不同粘弹性体系驱扫盲端残余油的过程 ,并利用界面化学理论 ,解释了驱油过程中产生的界面现象 ,揭示了聚合物、三元复合体系粘弹性效应作用的差异、界限 ,以及粘弹性效应对提高微观驱油效率的不可忽视的作用。聚合物溶液可以很好地驱替盲端油 ,但因刚性水膜的存在而不适于水驱后亲油或中性盲端残余油。三元复合体系具有较强的驱替盲端残余油能力 ,一方面低界面张力可破坏水膜 ,三元复合驱替液深入盲端 ;另一方面 ,体系的粘弹性则使三元复合驱替液接触到更多的残余油。

The largescale industrial application of polymer flooding has been put in practice in Daqing oil field. The field experiments of ASP flooding have gotten great success too. In order to improve two technologies more perfect to apply sufficiently and cognize the displacement mechanism, the residual oil displacement process of various viscoelastic systems in deadend pores has been studied comparatively on microscopic imitated models. And the interfacial phenomena in oil displacement process have been interpreted by the interface chemistry theory. The results have revealed the differences and margin of the viscoelasticity effect in polymer and ASP, and its necessary function on improving the microscopic displacement efficiency. The polymer solution can displace the oil in deadend pores very well but not the residual oil of water flooding in lipophilic or neutral deadend pores due to rigid water film. ASP system has a strong capacity of displacing the residual oil in deadend pores, not only the low interfacial tension can break the water film to make ASP more easily go deep into the deathend pores, but also the viscoelasticity makes ASP displacement fluid touch with more residual oil.