微生物驱油过程中模拟地层条件对微生物生长的影响

The Effect of Simulating Formation Condition on Microbial Growth in MEOR

微生物驱油过程中不同的地层条件对微生物的生长会产生明显的影响。本实验模拟胜利油田孤岛中一区Ng3区块地质条件,考察了地层水、地层多孔介质（石英砂）及含油多孔介质对微生物生长的影响。使用了两种不同配方的激活剂,配方a：1g/L葡萄糖、0.15g/L蛋白胨、0.05g/L酵母粉、0.1g/L硝酸铵、0.05g/L磷酸氢二铵;配方b：5g/L淀粉水解液、0.1g/L硝酸铵、0.1g/L磷酸氢二铵、1g/L尿素。结果表明,地层条件下多孔介质对微生物的生长影响较大,与单纯地层水培养相比,多孔介质条件下的微生物镜检菌数较低,这与多孔介质对菌体的吸附性有关。在不同的激活剂作用下,淀粉水解液的效果优于葡萄糖,淀粉水解液激活后溶液的pH值由8降至5,并产生较多小分子酸,这有利于微生物采油效果的持续性。镜检表明,多孔介质可吸附的菌数大于104个/mL,这对于微生物在多孔介质内生长繁殖有较好的促进作用。

The microbial growth was obviously effected by different geologic condition in MEOR. The effect of produced water, porous medium （quartz sand） and porous medium with crude oil on microbial growth was studied in simulated Zhongyi area reservoir condition. Meanwhile two activators were used, formula a was： 1 g/L glucose, 0.15 g/L peptone, 0.05 g/L yeast powder, 0.1 g/L ammonium nitrate, 0.05 g/L diammonium phosphate, and formula b was： 5 g/L starch hydrolysate, 0.1 g/L ammonium nitrate, 0.1 g/L diammonium phosphate, 1 g/L urea. The results showed that the microbial density was more in produced water than that in porous medium, which related to the adsorption of microbe in porous medium. The effect of starch hydrolysates was better than that of glucose. The solution pH value reduced from 8 to 5 obviously after microbe activated by starch hydrolysates. At the same time the small molecule acid was produced much more, which would increase the durative of MEOR. The microscopic examination results showed that the microbe was absorbed above 104cells/mL in porous medium, which was benefited for the growth in-situ of microbe in the cores.