采出程度对内源微生物驱油效果的影响研究

Influence of Recovery Degree on Indigenous Microbial Displacement Effect

为探索油藏采出程度对内源微生物驱油效果的影响,采用填砂岩心开展内源微生物驱油物模实验,研究采出程度(10%、20%、30%、40%、50%)对内源微生物驱油效果的影响。实验结果表明,向不同采出程度岩心注入激活剂后,内源微生物均达到3×108个/m L,但随着二次水驱细菌浓度下降幅度不同,岩心采出程度越高越容易形成主流通道,二次水驱过程中微生物很容易随主流通道被冲刷出去,微生物滞留时间较短最终浓度低,影响内源微生物驱油效率。采出程度低于30%时内源微生物驱油可提高采收率9%以上,驱油效果较明显。

The physical model experiments of indigenous microbial displacement were carried out by using sand filling cores in order to discuss on the influence of recovery degree（ 10%,20%,30%,40%,50%） on indigenous microbial displacement effect. The experimental results show that,the concentration of indigenous microorganisms all reached to 3 × 108 cell/m L after activating agents were injected into the cores with different recovery degree. However,with the decrease of the microorganism concentration in secondary water flooding,big channel was more easily formed in the cores with higher recovery degree,and microbes are easily washed out with the mainstream channel,which makes the residence time of microorganisms in the cores shortened and the efficiency of indigenous microbial displacement reduced. When the recovery degree is below 30%,the indigenous microbial recovery can increase recovery factor by more than 9%.