A novel way to enhance the oil recovery ratio by Streptococcus sp. BT-003.

Degrading hydrocarbon by Streptococcus sp. BT-003 as a kind of microbe for oil recovery was analyzed in this paper. The Streptococcus sp. BT-003 showed that it could use crude oil as the sole source of carbon and produce organic acid, bio-gas and polysaccharide which were propitious to emulsify and reduce the viscosity of crude oil. After cultivating 8–14 h, the viscosity of crude oil reduced from 8000–15000 mPa · s to 50–250 mPa · s. The content of organic acid increased 8–15 times, and carbon dioxide and polysaccharide reached 55 ml/l and 8 g/l respectively. Paraffin and resin reduced by 60–95%, and light components increased obviously. Fluid rheology was better than before, the interfacial tension between the crude oil and water were reduced effectively. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)