枯草芽孢杆菌提高原油采收率的物模驱油实验

Physical simulation experiment of oil displacement by bacillus subtilis for enhanced oil recovery

关键词:  枯草芽孢杆菌  生物表面活性剂  发酵工艺  乳化降解  物理模拟 

Key words:  bacillus subtilis  biosurfactants  fermentation process  emulsification biodegradation  physical simulation

摘要:

针对目前常规采油开采技术的限制和原油采收率较低等问题,本研究采用单因素法对一株从油污中分离的枯草芽孢杆菌(Bacillus subtilis 32811)代谢产生物表面活性剂的发酵条件进行优化并进行微生物驱油实验。优化条件实验确定了以葡萄糖为唯一碳源,最佳的无机培养基配方(g/L):ρ(C₆H₁₂O₆)30.0,ρ(NH₄NO₃)1.0,ρ(KH₂PO₄) 4.1,ρ(Na₂HPO₄·12H₂O)14.3,ρ(MgSO₄)0.096,ρ(CaCl₂)0.0008,ρ(FeSO₄)0.0011,ρ(C₁₀H₁₆N₂Na₂O₈)0.0015。发酵液表面张力从65 mN/ m降至25 mN/ m。通过微生物对原油降解的物模驱油实验,得出原油出现乳化及原油重质组分含量明显降低的结果。物模驱油实验中分别注入发酵液及先注入微生物再注入无机培养液能提高原油采收率26.1%和31.4%。说明枯草芽孢杆菌有利于提高剩余油的采收率,具有良好的应用前景。 

Abstract:

Based on the limitation of conventional oil mining technology and the low oil recovery, in this study, with the method of single factor, the fermentation conditions of a strain of bacillus subtilis isolated from contamination soil was optimized, and microbial enhanced oil recovery experiment was carried on. Glucose was determined as the sole carbon source by optimized condition experiment, and the optimum medium formula was (g/L):C₆H₁₂O₆,30.0; NH₄NO₃,1.0; KH₂PO₄,4.1; Na₂HPO₄·12H₂O,14.3; MgSO₄,0.096; CaCl₂,0.000 8; FeSO₄,0.001 1; C₁₀H₁₆N₂Na₂O₈,0.0015. It was found that the surface tension of culture medium decreased from 65 mN/m to 25 mN/m. The physical simulation of oil displacement with microbial degradation indicated that the emulsification appeared during the treatment and biodegradation of crude oil resulted in decrease of heavy component in crude oil. In the oil displacement experiments, separately injected fermented liquid and injected microbes first then injected inorganic medium, the oil recovery enhanced of 26.1% and 31.4% respectively. Bacillus subtilis has good prospect in promoting the displacement of residual oil in reservoir.