Study on the application potential of lipopeptide fermentation broth in oil recovery

Microbial flooding is a new enhanced-oil-recovery technology for the petroleum industry. In this study, strain of Bacillus subtilis named SL-2 was isolated from oil-well-produced fluid. B. produces lipopeptide surfactin. The fermentation broth contains biosurfactants (1.2 g/L) with good surface and interfacial activities. Adding 7% to water reduces its tension 72 33.9 mN/m between hexadecane 40 1 mN/m. Environmental adaptability analysis revealed that can tolerate salinity 50 g/L NaCl temperature 120°C, they have strong emulsifying effect on oil phase as well emulsification stability owing their high shear viscosity. Water contact angle measurements showed changes wettability properties rock surfaces hydrophobic hydrophilic. A bio-oil-displacement system developed by combining xanthan gum, biopolymer viscosifying properties. has dual functions improving oil-displacement efficiency expanding sweep volume. results laboratory simulation experiments recovery bio-composite containing 18.7% higher than flooding. Therefore, field application potential. Direct preparation using liquid reduce purification cost biosurfactant lipopeptide, which economically conducive technology.