Development of an cultivation in oil reservoir for microbial enhanved oil recovery

本研究旨在建立油藏微生物提高采收率（MEOR）的培养方法，重点研究营养物和细菌在多孔介质中的运移现象。在本研究中，为了研究这些现象，进行了一些实验和数学分析。制作了一个二维玻璃微珠填充床，用于营养物和细菌运输现象的实验室实验。采用KC1溶液和乳酸菌（干酪乳杆菌，ATCC15883）对MEOR的营养物和有用菌进行复制，考虑溶液浓度差异引起的转化、混合扩散和浮力的影响，KCl溶液注入床层的实验结果与二维数学模型计算结果吻合较好。以细菌溶液生长至静相后进入床层的结果为例，证实了床层孔隙被细菌堵塞的堵塞现象。因此，在数学模型中，除了考虑转换、混合扩散和浮力等参数外，还考虑了更多表示堵塞和堵塞现象的参数。计算结果与实验结果吻合较好。利用数学模型，对储层渗透率分布的变化进行了实例研究。在计算时，渗透率由Kozeny-Carman方程给出。模拟结果表明，营养物和细菌的运移现象差异很大，但渗透性分布变化不大。

This study, which purpose is establishment of an culture method in oil reservoir for microbial enhanced oil recovery (MEOR), focused on transport phenomena of nutrients and bacteria in porous media. In this study, to investigate these phenomena, there were carried out some experiments and mathematical analyses.A two-dimensional packed-bed with glass beads was made for laboratory experiments of nutrients and bacteria transport phenomena. KC1 solution and lactic acid bacteria (Lactobacillus casei, ATCC15883) were applied to replicate nutrients and useful bacteria for MEOR, The experimental results by KCl solution injections into the bed showed good agreements with the calculations of the two-dimensional mathematical model considering the conversion, the mixing diffusion and the buoyancy force due to differences of the solution concentration. At the case of the results by the bacteria solution, which grew until static phase, into the bed, it was confirmed the clog phenomena which pores in the bed were plugged by bacteria. So, at the mathematical model, there were considered more parameters that indicated clog and declog phenomena in addition to the parameters of the conversion, the mixing diffusion and the buoyancy force. The calculation results showed good agreements with the experimental results.Using the mathematical model, the cases studies were carried out that the distributions of permeability were changed in oil reservoir. At the calculations the permeability was given by Kozeny-Carman's equation. The results of simulation showed that the transport phenomena of nutrients and bacteria were very different with the little change of permeability distributions.