Enterobacter cloacae as biosurfactant producing bacterium: Differentiating its effects on interfacial tension and wettability alteration Mechanisms for oil recovery during MEOR process

Isolation and screening of Bacillus subtilis MJ01 for MEOR application: biosurfactant characterization, production optimization and wetting effect on carbonate surfaces

“…In this work, contact angle change from ~ 110° to ~ 90° was observed and it was concluded that biosurfactant has minor effect on the wettability. In the case of dolomite surfaces, Sarafzadeh et al (2013) and Rabiei et al (2013) from results of Amott tests showed that biosurfactant produced by Enterobacter cloacae changes wettability from strongly water-wet to neutral wet state. Despite these literatures, effect of biosurfactant on oil-wet calcite surfaces, which can be considered as a representative of carbonate reservoirs, was still an open question.…”

“…The ideal limit is the maximum feasible yield of biosurfactant, and the economical limit is the yield of biosurfactant by considering two important facts. The first evidence is that the extraction of biosurfactant from culture medium is not feasible both technically and economically; therefore, the raw biosurfactant in culture broth could be used directly for the injection process (Rabiei et al 2013;Sarafzadeh et al 2013;Souayeh et al 2014). The second fact is the components of culture medium should be compatible with reservoir connate water to prevent formation damage.…”

“…MEOR is a biologically based technology, which mobilizes trapped oil by utilization of bioproducts through both in situ and ex situ processes. This technology has different mechanisms such as gas production, improving mobility ratio by oil viscosity reduction, biopolymer production, bioclogging, interfacial tension (IFT) reduction and wettability alteration (Armstrong and Wildenschild 2012a;Lazar et al 2007;Sarafzadeh et al 2013;Sivakumar et al 2013;Soudmandasli et al 2007;Zhao et al 2017). However, the last two mechanisms have great importance, since IFT and wettability control capillary forces in porous media.…”

Research Status of Surfactant Producing Microbiology in MEOR: A Review

“…SEM images taken from the treated cores showed biofilm formation on the rock pore surfaces, which is responsible for rock surface wettability alteration (Sarafzadeh, 2013). The fermentative production of biosurfactants by five Bacillus strains in a bench-scale bioreactor and evaluation of biosurfactant-based enhanced oil recovery using sand pack columns were investigated.…”

Laboratory studies of rice bran as a carbon source to stimulate indigenous microorganisms in oil reservoirs

“…Acids may increase carbonate rock porosity and permeability, thereby promote the exudation of remained oil (Sen 2008). Emulsifiers can emulsify crude oil, lower its viscosity and improve its fluidity (Banat et al 2010;Dastgheib et al 2008;Kitamoto et al 2009;Sarafzadeh et al 2013;She et al 2011). The multiple effects of various metabolites improve oil flooding and thus enhance crude oil recovery.…”