Experimental investigation of the impact of biosurfactants on residual-oil recovery

Ukwungwu, SV; Abbas, AJ; Nasr, GG

Abstract

The increasing high price of natural gas and oil with
attendant increase in energy demand on world markets in recent years
has stimulated interest in recovering residual oil saturation across the
globe. In order to meet the energy security, efforts have been made in
developing new technologies of enhancing the recovery of oil and
gas, utilizing techniques like CO2 flooding, water injection, hydraulic
fracturing, surfactant flooding etc. Surfactant flooding however
optimizes production but poses risk to the environment due to their
toxic nature. Amongst proven records that have utilized other type of
bacterial in producing biosurfactants for enhancing oil recovery, this
research uses a technique to combine biosurfactants that will achieve
a scale of EOR through lowering interfacial tension/contact angle. In
this study, three biosurfactants were produced from three Bacillus
species from freeze dried cultures using sucrose 3 % (w/v) as their
carbon source. Two of these produced biosurfactants were screened
with the TEMCO Pendant Drop Image Analysis for reduction in IFT
and contact angle. Interfacial tension was greatly reduced from 56.95
mN.m-1 to 1.41 mN.m-1 when biosurfactants in cell-free culture
(Bacillus licheniformis) were used compared to 4. 83mN.m-1 cell-free
culture of Bacillus subtilis. As a result, cell-free culture of (Bacillus
licheniformis) changes the wettability of the biosurfactant treatment
for contact angle measurement to more water-wet as the angle
decreased from 130.75o to 65.17o. The influence of microbial
treatment on crushed rock samples was also observed by qualitative
wettability experiments. Treated samples with biosurfactants
remained in the aqueous phase, indicating a water-wet system. These
results could prove that biosurfactants can effectively change the
chemistry of the wetting conditions against diverse surfaces,
providing a desirable condition for efficient oil transport in this way
serving as a mechanism for EOR. The environmental friendly effect
of biosurfactants applications for industrial purposes play important
advantages over chemically synthesized surfactants, with various
possible structures, low toxicity, eco-friendly and biodegradability.

Keywords—Bacillus, biosurfactant, enhanced oil recovery,
residual oil, wettability.

Citation

Ukwungwu, S., Abbas, A., & Nasr, G. (2016). Experimental investigation of the impact of biosurfactants on residual-oil recovery

• Journal Article Type: Article
• Publication Date: Jan 1, 2016
• Deposit Date: Mar 22, 2016
• Publicly Available Date: Apr 13, 2016
• Journal: International Journal of Biological, Biomolecular, Agricultural, Food and Biotechnological Engineering
• Volume: 10
• Issue: 3
• Pages: 130-133
• Publisher URL: http://www.waset.org/Publications/?path=Publications&q=Experimental+investigation+of+the+impact+of+biosurfactants+on+residual-oil+recovery&search=Search