African Journal of Biotechnology Vol. 5 (5), pp. 453-456, 1 March 2006   

ISSN 1684–5315 © 2006 Academic Journals        

Full Length Research Paper

Enhancement of recovery of residual oil using a biosurfactant slug

G. C. Okpokwasili* AND A. A. Ibiene

Department of Microbiology,  University of Port Harcourt,  P. M. B. 5323,  Port Harcourt,  Nigeria.

*Corresponding author. E-mail: gidsilman@yahoo.com.

Accepted 20 January, 2006

A laboratory investigation of the mobilization and displacement of residual oil in a sand-pack using biosurfactant slug was conducted. The biosurfactant employed was extracted from a culture of Pseudomonas sp. grown on kerosine- supplemented mineral salts medium. Characterization of the biosurfactant extract revealed a mixture of glycolipid and phospholipid in a ratio of 3.35:1.  The irreducible water saturation (S_wi) and initial residual oil saturation (S_or) of the sand-pack were 0.280 ± 0.003 and 0.373 ± 0.006, respectively. Core flooding experiment showed that an optimum oil recovery of 52.19% of the in-place residual oil was achieved at biosurfactant incubation time (BIT) of 120 h. These results suggest that biosurfactant produced by Pseudomonas species is a potential “candidate” for microbially enhanced oil recovery.        

Key words: Laboratory investigation, enhanced oil recovery, biosurfactant slug, Pseudomonas species.