动态驱替内源微生物生长代谢与驱油效率关系

油藏内源微生物的生长代谢活性直接影响内源微生物驱油技术现场实施效果,摇瓶培养及一维物理模拟实验手段无法真实模拟微生物动态驱替过程。利用三维物理模拟实验体系,开展了内源微生物驱油过程中内源微生物群落生长代谢规律研究。研究结果表明:由于多孔介质对激活剂的滞留和吸附作用,三维模拟动态驱替体系中内源微生物群落激活剂消耗C∶N∶P比传统微生物培养的比例低,而且不同生长阶段的组分消耗比例不同;模拟油藏环境的动态驱替体系中,内源微生物群落生长代谢呈现出与传统微生物培养相似的延滞期、对数生长期、稳定期和衰亡期,但生长周期明显延长。内源微生物群落生长代谢规律与生产动态之间存在明显的对应关系,生长延滞期含水无明显变化,对数生长和稳定期含水快速降低,进入衰亡期后驱替效率快速降低,该认识与现场产出液微生物浓度与生产动态变化规律一致。

Relationship between the growth and metabolism of indigenous microorganisms and oil displacement efficiency during dynamic displacement

The growth and metabolic activity of indigenous microorganisms in reservoirs directly affects the on-site implementation effect of indigenous microorganism oil displacement technology. The dynamic microorganism oil displacement process cannot be truly simulated through shaking culture and one-dimensional physical simulation experiments. Using the three-dimensional physical simulation experiment system, a study is carried out on the growth and metabolism of indigenous microbial community during indigenous microbial flooding. This study confirms that due to the retention and adsorption of activators in porous media, the consumption of activators (C∶N∶P)by the indigenous microbial community in the three-dimensionally simulated dynamic oil displacement system is lower than that by traditional microbial cultivation, and the consumption ratio of components is different in various growth stages. The study also confirms that in the dynamic oil displacement system simulating the reservoir environment, the growth and metabolism of the indigenous microbial community show lag phase, logarithmic growth phase, stable phase, and decline phase, which is similar to traditional microbial cultivation; howerver, the growth cycle was significantly extended. There is a clear correspondence between the growth and metabolism laws of indigenous microbial community and the production performance. There is no significant change in water content during the lag growth phase. The water content decreases rapidly during the logarithmic growth and stable phases, and the displacement efficiency decreases rapidly after entering the decline phase. This understanding is consistent with the change laws of microbial concentration of the on-site produced fluid and production performance. As revealed by this study, the macro-growth and metabolism laws of indigenous microbial community during dynamic oil displacement by indigenous microorganisms provide a theoretical basis for analyzing the on-site implementation effect of indigenous microbial flooding and dynamically controlling the technique process during implementation.