Bibi Hakimeh oilfield consists of more than 145 oil producing wells. Its Oligomiocene Asmari reservoir is dominantly made of limestone. The act of a reverse fault on the north flank of Bibi-Hakimeh Field caused a significant thickness reduction in Gachsaran formation in the way that in some drilled wells, members No. 2, 3, 4, 5 and 6 of Gachsaran cap rock have been totally eliminated. This causes locating Asmari reservoir in a shallower level and therefore lowers reservoir temperature in the North flank already have made the reservoir suitable for a microbiological enhanced recovery. The long term production of this reservoir caused a significant reservoir pressure drop. Therefore; the recovery has been performed using Basilus with Ex-Situ method. In this case study, the feasibility of surfactant production in several oil wells has been accomplished. A high temperature resistant Basilus has been selected to evaluate the production ability of biosurfactant. This bacterium has been chosen after performing all morphological, biochemical and genetic studies. This bacteria shows a good resistance against the temperature in such manner that its emulsification, surface tension and inter surface tension abilities do not change after 15 min in an autoclave process at 120° C. In the next step, the temperature, pH, Carbon, N2 and other factors have been optimized for biosurfactant production. Considering the lithology of the reservoir using this type of bacterium. This can be a good way to produce lipopithidic biosurfactant by Ex-Situ method in Asmari to enhance oil recovery. The basilus, which has good resistance against temperature and acts well in pressurized environments, can be considered as a good candidate for tertiary enhanced oil recovery process. The best method to produce basilus in B5 is the Formislink method.
1] Saxton J., “Geology of the middle east”, Geology of Arabia peninsula USGS journal,.Vol. 30, No. 3, pp. 225-238, 2006.
 Beydoun Z.R., Hughes Clark M.W. & Stonely R., “Petroleum in Zagros Basin: A late Tertiary foreland basin overprinted on to the outer edge of vast hydrocarbon- rich Paleozoic- Mesozoic passive- margin shelf”, American Association Petroleum Geology journal, Vol. 23, No. 5, pp. 309-339, 1992.
 Cassidy D.P. & Hudak A.J., “Microorganism selection and Biosurfactant production in a continuously and periodically operated bioslurry reactor”, Journal of Hazardous Materials, Vol. 38, No. 6, pp. 253-278, 2001.
 Bognolo G., Biosurfactant as emulsifying agents for hydrocarbons Colloids and Surfaces, 2th Ed., Mc-sun Inc, 1991.
 Cooper D.G., Liss S.N. & Ferment. “Surface activities of Mycobacterium and Pseudomonas”, J. Ferment. Technol, Vol. 59, No. 2, pp. 97-112, 1989.
 Bessor F. & Michel G., “Biosynthesis of iturin and surfaction by Bacillus subtilis. Evidence for amino acid activating nzymes”, Biotechnol. Lett journal., Vol. 14, No. 10, pp. 16-35, 1999.
 Aalbry E.A. & Mandel M., “Optimal conditions for mutagenesis by N-methyl-N-nitro-N-nitrosoguanidine in Escherichia coli K12”, Biochemical and Biophysical Resarch communications, Vol. 18, No. 7, pp. 90-98, 1965.
 Cooper D.G. & Goldenbergy V.A., “Surface active agents from two Bacillus species”, Appl. Environ. Microbiol, Vol. 18, No. 9, pp. 227-236, 1999.
 Cooper D.G. & Paddock B.G., “Production of a biosurfactant from Torulopsis bombicola”, Appl. Environ. Microbiol, Vol. 46, No. 14, pp. 26-39, 1983.
 Banat I.M., “Biosurfactants production and possible uses in Microbial Enhanced oil recovery and oil pollution Remediation”, Bioresource Technology, Vol. 51, No. 1, pp. 12-26, 1995.
 Black wood K.S. & Turenne C.Y., “Penetration of sulfate Reducers through a poreus North sea oil Resertooir, AppLIED and environmental microbiology”, Jornal of chemical microbiology, Vol. 42, No. 16, pp. 26-37, 2004.
 Zekriy A., “Optimization of Microbial Fleeding in carbonate Reservoirs”, society of petroleum Engineers interational, Vol. 96, No. 8, pp. 223-242, 2002.