大庆油田聚驱后油藏驱油本源菌研究

Characteristics of Indigenous Microorganisms for Enhancing Oil Recovery after Polymer Flood in Daqing Oilfield

从大庆油田聚合物驱后油藏中分离培养产生物表面活性剂本源菌,并对其代谢特性,生化特征和原油降解降黏性能进行了综合评价。实验结果表明,筛选出的3株本源菌XDS1,XDS2和XDS3,均为短杆状,属芽孢杆菌类;培养试验表明3株菌发酵液排油圈大于4.5 cm、表面张力30 mN/m左右。这3株菌在45℃较优条件下培养,6小时即达到高峰期;3株菌对大庆5个原油样的降解率均达50%以上,最高达84%,三株菌按体积比1∶1∶1的混合菌XDS123降解率高达90%。3株菌中,XDS3作用于307号原油后发酵液表面张力降低到25.3 mN/m,XDS1作用后的306号原油黏度降低23.6%,发酵液pH值均小于7,说明产出了低相对分子质量有机酸,3株菌及代谢物与307号大庆原油协同作用后乳化较好,表现出较好的驱油应用潜力。

Three biosurfactant-producing indigenous microorganisms were isolated from the oil reservoirs in Daqing after polymer flood finished and their metabolic and biochemical properties and degradability for crude oils were assessed comprehensively.These stains,notated as XDS1,XDS2 and XDS3,were identified all as bacillus.For the cultivation cultures of these strains,the oil spreading value was measured,being of 〉4.5cm,and the surface tension was about 30 mN/m.Under fairly good cultivation conditions at 45℃,the 3 strains grew well and reached their volume climax within 6 hrs.The percent degradability for 5 crude oils of Daqing was 〉50% with the highest value of 84% by these 3 strains and was as high as 90% by the mixture of the 3 strains in equal volume ratio,notated as XDS123.The surface tension of the cultivation culture of XDS3 on crude oil #307 was lowered to 25.3 mN/m;the viscosity of the crude oil #306 subjected by XDS1 was lowered by 23.6%;all the cultivation cultures had pH value 〈7,indicating production of low molar mass organic acids;the crude oil #307 subjected by these 3 strains and their metabolites was well emulsified and this phenomenon showed good latent ability of these strains in MEOR.