Enhanced recovery of Bonny light crude oil from unconsolidated porous media by two Pseudomonas species

Aims: Pseudomonas fluoresens SL83 and Pseudomonas mallei SL63 were employed in tertiary (enhanced) recovery of Bonny light crude oil in unconsolidated porous soil matrix. Methodology and results: The porous matrix was made from soil of various types and grain sizes [coarse sand (500 μm), fine sand (212 μm) and silt (106 μm) of varying percentage composition]. Porosity of the composite soil matrices were determined to be: 25%, 35% and 40%. Residual oil saturation and irreducible water saturation were determined before the oil recovery test was carried out. The rate of oil recovery after reducing the viscosity of the crude oil showed that P. fluoresens had the recovery rate of 33.3%, 23.8% and 20.8% while P. mallei had 28.5%, 22.2% and 16.7% at 40%, 35% and 25% porosities respectively. Conclusion, significance and impact of study: The amount of oil recovered through microbial enhanced oil recovery in this study is quite significant which further confirms the potential of P. fluoresens and P. mallei biosurfactants as veritable material for use in enhanced recovery of crude oil.