| Microbial enhanced oil recovery (MEOR) is a popular method today in oil production that relies on microorganisms and their metabolic products to mobilize residual oil. Early in 1946 people began to study the application of biosurfactants in oil production, when Zobell discovered that microbe-producing biosurfactants are one of the mechanisms of MEOR. Biosurfactants lower the oil-water interfacial tension, letting the oil droplets release from the sandstones surface, and reduce the viscosity of heavy oil to help its flow. The production of biosurfactants in aerobic environment has been comprehensively researched. Rhamnolipid for instance, has been extensively studied and applied because of its remarkabl surface activity and emulsifying ability. |
Biosurfactants in MEOR
Until today, it remains at a stage where we have to produce our biosurfactant like rhamnolipid at a bioreactor and then injected them into the oil reservoir. The process of product purification and transportation is very costly and complex, which makes it too unpractical to employ in offshore oil wells. In the meantime, the chance for biosurfactants molecules to meet residual oil along the water pathway is very small. We can’t target the oil droplets separated all over the oil field which is often half wrapped by sandstones. Thus the increase of oil output depends largely on the amount of biosurfactants we pump into the well, causing its low efficiency.
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