不同采出程度下微生物采油效果分析

Performance of Microbial Enhanced Oil Recovery Under Different Recovery Percentages of Reserves

为研究采出程度对微生物采油效果的影响，向不同采出程度的4组岩心中分别注入0.2倍岩心孔隙体积的接种有产表面活性剂菌、产聚合物菌的激活培养基。封闭岩心并置于油藏温度下对微生物进行培养。10d后再次对岩心进行驱替，用平板计数法检测水驱过程中产出液的菌体浓度变化。同时将采取微生物采油措施的岩心的驱油效率与不接种菌的岩心的驱油效率对照，观察采收率的提高幅度，发现采出程度不同时，驱替压力、菌体浓度、最终的驱油效率均不同。实验表明，采出程度导致的原油组分、油水体积比、油水渗流能力等参数的变化共同影响了微生物的生长繁殖及其代谢产物浓度和总量的积累，导致采收率提高的幅度随采出程度的提高呈先增大后减小的趋势。

In order to study the performance of microbial enhanced oil recovery under different recovery percentages of reserves, four groups of cores with different oil saturation extents were injected into 0.2 pore of the culture medium inoculated with the bacteria producing biosurfactant and biopolymer. Then the core was closed to cultivate the bacteria, in the reservoir temperature, beneficial for oil production. After 10 days, the water-oil displacement experiment was Carried out and the bacterial concentrations in the flooding water were detected by the plate count method. By comparing the oil displacement efficiency of the core inoculated with bacteria with that of the core without bacteria, it is shown that, in the process of the experiment, the displacement pressure, the bacterial concentrations and the final displacement efficiency all vary with the different recovery percentages of reserves. It is concluded that, with the different recovery percentages of reserves, the variations of oil components, oil-water phase ratio and the fluid ability affect the reproduction of microorganisms and the accumulation of its metabolite concentrations and the gross amount, as a result, the recovery efficiency increases firstly and then decreases with the continuous increase of the recovery percentage of reserves. The study provides some guidance in choosing the microbial strain and the time of the microbial enhanced oil recovery and the displacement rate.