Enhanced oil recovery from low permeability dolomite cores using biosurfactant produced by a Bacillus mojavensis (PTCC 1696) isolated from Masjed-I Soleyman field

A Bacillus mojavensis strain (PTCC 1696) which was isolated from an Iranian oil field was used to produce a lipopeptidic biosurfactant. The surface activity measurement with De Nouy ring detachment method showed that this biosurfactant is able to reduce the surface tension of the media and interfacial tension between aqueous phase and n-hexadecane to 26.7 and 0.1 mN/m respectively. The core flooding tests were carried out to evaluate oil recovery from carbonate reservoirs by this lipopeptidic biosurfactant. These tests were conducted at reservoir conditions using low permeability dolomite cores, live crude oil and reservoir formation brine. The experiments showed that the biosurfactant-assisted waterflooding method can be considered as a technique for oil recovery from carbonate formations. The results obtained in this study showed the potential of the biosurfactant produced by Bacillus strains for enhanced oil recovery even from low-permeability carbonate reservoirs.