聚驱后强弱碱三元体系极限驱油效果实验研究

随着大庆油田主力油层开发进入高含水阶段,急需聚合物驱后提高采收率接续技术方法。本文针对聚合物驱进入高含水阶段后进行三元驱的可行性展开了研究,利用达到超低界面张力条件的三元体系,模拟聚合物驱达到极限驱油效率后,开展三元体系极限驱油效果对比研究。结果表明:在聚合物驱达到极限采收率后,开展三元体系驱油能够进一步提高驱油效率,当弱碱三元体系中碱浓度较低时,聚驱后三元驱的采收率增加值较高,阶段极限采收率可达32.97%;当强碱三元体系中强碱浓度较高时极限采收率可达30.29%。在体系其他组成相同的条件下,基于强碱三元体系对注入系统和油层伤害较严重的问题,建议采用弱碱三元体系开展驱油生产。

The Impat Study of Alkali Types in ASP Systerm on Oil Displacement After Polymer Flooding

As the polymer flooding technology is in the high water cut stage of field development,oil EOR technology is facing new challenges,ASP flooding systems become an important and stable oil next succeeding methods.In this paper,the feasibility of ASP flooding after the polymer flooding into high water stage is studied.Used ASP system with the ultra-low interfacial tension conditions,carried out the oil displacement experiments after polymer flooding that it water cutting reached 100%,the final oil displacement efficiency of ASP systems were studied.The results showed that：Oil displacement efficiency after polymer flooding of ASP system can be further improved,when the stage water cutting of polymer flooding had reached 100%.With the lower concentration of sodium carbonate in ASP system,the ASP system can get the stage recovery is 32.97%.The best recovery addition of sodium hydroxide is 30.29%,it can be reached while the sodium hydroxide concentration is the highest concentration in the ASP system.Based on the formation damage problems of ASP system with sodium hydroxide is more serious,we recommend using ASP system with sodium carbonate to carrying out the oilfield production.