内源微生物驱油激活配方筛选评价指标探讨

通过室内摇瓶实验和岩心驱油实验,系统分析了油田内源微生物激活实验过程中各项参数的变化规律,包括激活内源菌总菌数、6类内源菌菌数,水相pH值、乙酸根离子质量分数、水相粘度、水相表面张力,油相粘度、密度,实验产出气体体积,油水乳化效果和岩心驱油提高采收率值等。不同激活实验结果表明:内源菌总菌数可增加3个数量级以上;有益内源菌菌数可增加2个数量级;水相中的乙酸根离子质量分数和水相粘度有所增加;实验中可以产出不同体积的气体,气体成分主要为CO2;油水乳化效果差异较为明显;岩心驱油提高采收率值为6%～9%;上述参数变化具有一定的规律性,与微生物驱提高采收率机理一致,可以作为内源微生物驱激活配方筛选的评价指标参数。

Study on activation blend evaluation for indigenous microbial flooding

Microbial activity tests are conducted using Shake-Flask test method and core activation method.Various parameters are analyzed herein,including total indigenous microbes live population,six types of indigenous microbes population,water phase pH,mass percentage of acetyl radical concentration,water phase viscosity,surface tension,oil phase viscosity,produced gas volume,oil/water emulsifying effects,oil displacing efficiency on cores,etc.Different activating experiment results show that,the total indigenous microbes live population can be increased to more than three orders of magnitudes,while the useful indigenous microbes population can be increased by two orders of magnitudes.There has been some increase in the mass percentage of acetyl radical concentration and water phase viscosity.Different volumes of gas can be produced during the experiment,with the main component of CO2 gas.There is significant difference in the oil/water emulsifying effects and the oil displacing efficiency of cores can be improved by around 6%-9% (OOIP).These rules are consistent with EOR mechanisms of microbial flooding,so they can be used as activation blend evaluation guidelines for indigenous microbial flooding.