Microbial Enhanced Oil Recovery (MEOR) as a tertiary oil recovery technique by using microorganisms’ activities for improvement of oil recovery from one of the Iran’s oil reservoir with special attention to the role of biosurfactant production on MEOR performance was evaluated experimentally. Some experiments by using orthogonal arrays of Taguchi method as an efficient technique for experiment design were planed and conducted to probe and evaluate the effects of microbial formulation on oil recovery efficiency and also the importance of biosurfactant production in oil recovery. All experiments performed in two main scale, flask size and simple core flooding system.
There were five parameters, which their effects and also their importance were studied: source of carbon, nitrogen and phosphorus quantity, type of microorganism, temprature and salt concentration each one in three levels. Final results showed that using microbial treatment in oil recovery causes increase of oil recovery efficiency in comparison with water flooding oil recovery with no microbial treatment and also final results proved that among different mechanisms of microbial oil recovery biosurfactant production has had a major role in this specific study.
The highest oil recovery efficiency among different experiments was about 14.3% when indigenous microorganism of Paydar oil field, which has been isolated from oil samples, was used with 2% sucrose as the main carbon source and 0.2% (NH4)2HPO4 at temprature of 450C.
The best result for biosurfactant production was observed when B. Subtilis was used with 2% sucrose as the main carbon source and 0.4% (NH4)2HPO4 in 1% salt concentration. Finally this study showed the relative possibility of MEOR application for Iran’s Paydar oil field.