胶质降解和生物乳化在稠油降黏中的作用

Effects of resin degradation and biological emulsification on the viscosity break of heavy oils

芽孢杆菌QB26是一株高温解烃菌,能以胶质为唯一碳源生长,在以2%胶质为唯一碳源的无机盐培养基中,55℃好氧振荡培养14d,胶质降解量可以达到45.96%;同样培养条件下,该菌发酵液可以较好地乳化等体积的稠油(55℃条件下黏度为1 146 mPa.s),稠油降黏率达到66.49%。该菌与一株假单胞菌T-1复配(VQB26∶VT-1=1∶1)后作用稠油,可以显著改善稠油的乳化效果(乳化稳定性增强,平均乳化粒径为17.88μm,减小粒径67.3%),此时的稠油乳化黏度为5.11 mPa.s,仅为初始黏度的0.45%。物理模拟驱油实验结果表明,该体系在均质岩心和非均质岩心中提高模拟油藏的原油采收率分别为14.4%和22.38%,达到了降解胶质和生物乳化的双重降黏效果,大幅度提高了原油的流动性。

Bacillus sp. QB26 is a strain of thermophilic hydrocarbon-degrading bacteria which can utilize resins as the sole carbon source for growth. In the mineral salt medium（MSM） with 2% resins as the only carbon source, the degradation rate of resins could reach 45.96% after the 14-day aerobic culture at 55℃. Under the same conditions, the QB26 fermentation could perfectly emulsify the same volume of a heavy oil（with the viscosity of 1 146mPa.s at 55℃） by reducing the viscosity by 66.49%. When this oil was degraded by the combination of QB26 and pseudomonas sp. T-1 （VQB26 ： VT 1 = 1 ： 1 ）, we found emulsifying effects improved greatly because the emulsion stability increased and the average partial size was 17.88 μm. , being reduced by 67.3%. Meanwhile, the vis cosity of the heavy oil was 5.11 mPa·s, only 0.45% of the original viscosity. In addition, experiments of the indoor homogeneous/ heterogeneous core physical simulation showed that this system could improve the oil recovery of the simulated reservoir by 14.4% and 22.38%, respectively. These experiments achieved dual effects of viscosity break by means of resin biodegradation and biological emulsion, which can significantly improve the mobility of crude oils.