Factors Affecting the Production of Biosurfactants and their Applications in Enhanced Oil Recovery (EOR). A Review

Biosurfactants are surface-active compounds synthesized by microbes. They have the ability to reduce the surface tension of a liquid and interfacial tension (IFT) between two different phases. Thus, they can be applied in water-oil emulsification. The development of enhanced oil recovery (EOR) technology has led to increased interest in biosurfactants. The purpose of this review was to compile information on important components of biosurfactant production. Understanding the characteristics of biosurfactants, especially IFT derivation and effects of alterations in the wettability of reservoir rocks can aid the applications in EOR. Both the microbe type and growth substrate influence the yield and type of biosurfactant produced. The type of fermenter also affects the efficiency of surfactant production. The use of batch type fermentors and the use of Pseudomonas and Bacillus bacteria in the previous research was superior whereas the sugar group and plant base oil as substrates. The measurement methods of biosurfactants in microbial culture are of considerable importance to be done prior to characterization of biosurfactant products. Furthermore, some reservoir components discussed in this review are the keys to the success of biosurfactant flooding in the field.