Potential use of a local bacterium in microbial enhanced oil recovery
Nowadays the world relies heavily on crude oil and petroleum-based products, but 35–55% of crude oil is generally left behind in the reservoir after primary and secondary recoveries. Microbial enhanced oil recovery (MEOR) is remarkable for its flexibility and economy which could be achieved by applying in the oil field. MEOR is a method that utilizes microorganisms or their bio products to increase oil recovery at the tertiary stage. This technique has the potential to reduce the cost of the process in the extraction of oil remaining in the field.
It was aimed in this research to isolate a local bacterial strain from oil mud and evaluate its efficacy to be used in MEOR. A strain of the genus Bacillus is characterized by its ability to produce biosurfactant with emulsification index of 60% with kerosene. The bacterium was tested in a sand packed column, a bench-scale approach to evaluate oil recovery. It is an economic model to simulate the oil reservoir operation usually conducted in reservoirs. By applying this model, the bacterium was able to extract 23.5% of crude oil. An oil field lab scale simulation system was constructed to test the suitability of the bacteria to be used in the oil field and its adaptation to field’s extreme conditions. The experiment was conducted over one week to compare the application of water, commercial chemical surfactant and bacteria to extract the oil. The bacterium was able to extract 40% of the oil with 10% increase compared to water. Only13% of oil was extracted using the commercial chemical surfactant .
The project offers an economically cheap and promising candidate for MEOR applications prospect to enhanced oil recovery to be applied on actual oil fields in Egypt. Further improvement and more detailed studies are required.