水溶性ポリマー生産微生物を用いたMEORの数値実験
2004 年 69 巻 5 号 p. 563-573
詳細
2004 年 69 巻 5 号 p. 563-573
Our group has carried out the various studies and experiments on MEOR process with the microbe producing water-soluble polymer. Based on these efforts, the basic performance and mechanism in this process were well simulated by computation experiment in the previous paper.
In this paper, our group carried out the case studies of this process using the computation experiments and suggested the important conditions and its sensitivity of the effect.
First, the effect of reservoir conditions was estimated by changing permeability distribution, oil viscosity and oil saturation. The ratio of the enhanced oil recovery by this process was high at the all conditions of reservoir. It should be noted that this process was effective in any types of reservoir without restrictions of permeability distribution, oil viscosity variety. It was shown that the application of this process in the earlier stage of development was more effective because oil recovery was accelerated in the earlier stage by increase of oil saturation.
Next, the effect of cultivation conditions was estimated by changing nutrient concentration, shut-in time for incubation and fluid property. The ratio of the enhanced oil recovery became higher by increase of nutrient concentration, but they had not proportionality relation. Therefore, it is necessary to optimize nutrient concentration for target reservoir by estimating the economical efficiency. It was suggested that taking shut-in at least for 2 days was one of necessary procedure for higher enhanced oil recovery.
Third, the effect of injection conditions was estimated by changing injection volume, rate of microbe, nutrient solution and injection cycle of the solution and water. It was shown that those conditions must be optimized by considering economical efficiency for target reservoir.
In conclusion, it was suggested that the enhanced oil recovery by this MEOR process can be optimized by selecting suitable conditions to reservoir characteristics and by controlling conditions of cultivation and injection.
