微生物驱油产出液循环利用方法研究

Study of the methods for recycling produced fluid in microscopic oil displacement

关键词:  微生物驱油  循环  驱油效果  提高采收率  注入成本 

Key words:  microscopic oil displacement  recycling  oil displacement efficiency  enhanced oil recovery  injection cost

摘要:

为了探究新疆油田六中区微生物驱油现场产出液循环利用的可行性,在对产出液组成及浓度分析研究的基础上,利用物理模拟方法研究了产出液直接回注、添加营养后注入、地面扩大培养注入以及注入新油藏4种产出液循环利用方式对驱油效果的影响。实验表明,产出液中营养浓度仅为注入浓度的10%左右,已不能满足直接注入要求,需要添加营养才能进一步提高采收率。4种产出液循环利用方式对比发现:有益菌及代谢产物都可以循环利用,产出液地面扩大培养后驱油效果最好,菌浓达到2.1×10⁸ cfu/mL,表面张力由71.6 mN/m降低至55.9 mN/m,提高采收率14.2%。该研究能够进一步降低驱油剂成本并为产出液循环利用提供参考。 

Abstract:

In order to explore the feasibility of recycling on-site produced fluid in microscopic oil displacement in Xinjiang oilfield, based on the research of the composition and concentration of produced fluid, the method of physical simulation was used to research the oil displacement efficiency of four produced fluid injection methods:injecting produced fluid into the core without adding any nutrition, adding nutrition to produced fluid, adding nutrition to produced fluid and then cultivating it on the ground, and injecting produced fluid into a new core. Experimental results show that the nutrition concentration of produced fluid was just 10% of injecting fluid and can not meet the requirement of direct re-injection. Therefore, it needed adding nutrition to enhance oil recovery further. Comparing four produced fluid injection methods, it shows that the bacteria and metabolites of produced fluid can be recycled, and produced fluid injection method of adding nutrition to produced fluid and then cultivating it on the ground has the best oil displacement efficiency. The surface tension of produced fluid reduced from 71.6 mN/m to 58.9 mN/m, bacteria concentration was up to 2.1×10⁸ cfu /mL, and enhanced oil recovery was up to 14.2%. The research can reduce injection cost further and provide certain reference significance for recycling produced fluid in microscopic oil displacement.