采油微生物在微驱过程中的生长、运移及分布规律

The growth, migration and distribution law of microbes during microbial displacement oil

摘要:

【目的】深入了解现场微生物驱油机理、效果评价标准及影响因素。【方法】结合现场微生物驱油过程产出液的跟踪监测及室内物模实验对微生物在地层中的生长繁殖、运移及分布规律进行研究。【结果】结果表明, 通过从水井注入的外源微生物在油藏中能够有效生长繁殖, 而且注入的营养液也能够激活内源微生物, 但由于地层渗透率及营养液浓度的影响, 产出液菌浓要比注入菌浓低1?2个数量级; 葡萄糖的快速降解以及地层对微生物的过滤及吸附作用使大量的微生物停留在近井地带, 仅有部分微生物能够从生产井采出, 而且其运移速度要比营养液慢。【结论】地层渗透率和产出液中营养物浓度是影响微生物数量及分布的两个关键因素, 现场微生物驱油产出液中的菌浓一般很难达到106个/mL以上, 该研究结果对微生物驱油技术的发展和应用具有重要意义。

关键词:微生物驱油, 现场应用, 物模实验, 微生物运移分布

Abstract:

[Objective] To understand the field of microbial oil displacement mechanism, evaluation standards and its influence factors. [Methods] The growth, migration and distribution law of microbes during microbial displacement oil were studied based on site tracing monitoring during field microbial displacement oil and the physical model experiment in laboratory. [Results] The results show that the exogenous microbes injected from water injection well can grow and reproduce well in oil reservoir, and the injected nutrient solution is also capable of activating indigenous microbes, but the microbes concentration in produced fluid is lower 1?2 orders of magnitude than injected microbes concentration due to the formation permeability and nutrient concentration. Because of the rapid glucose degradation and the microbes filtration and adsorption by formation, the amount of microbes stay near the wellbore and only part of them can be produced from the corresponding oil well. Moreover, the migration rate of microbes is slower than nutrition. [Conclusion] The formation permeability and the nutrient concentration of output liquid are the two key factors on microbial quantity. The microbes concentration in produced fluid is difficult to exceed 106 cells/mL on site. The results of the study have a great significance for the development and application of microbial displacement oil technology.

Key words:Microbial displacement oil, Field application, Physical model experiment, Microbes migration and distribution