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PRINT ISSN : 2319-7692
Online ISSN : 2319-7706 Issues : 12 per year Publisher : Excellent Publishers Email : editorijcmas@gmail.com / submit@ijcmas.com Editor-in-chief: Dr.M.Prakash Index Copernicus ICV 2018: 95.39 NAAS RATING 2020: 5.38 |
After the three-stage recovery processes employing physical, mechanical and chemical methods fail to recover the remaining crude oil. Biotechnology plays an important role to enhance crude oil recovery from the oil reservoirs so as to solve stagnant petroleum production Microbial enhanced oil recovery (MEOR) is an biotechnologically enhanced oil recovery process which involves injecting specially selected natural bacteria into the reservoir or stimulating indigenous reservoir microbes to produce certain metabolic events that lead to improvement of oil recovery. This paper reviews the mechanisms of oil release and the use of microbes and their metabolic products to enhance oil recovery. Alteration of oil/rock/water interfacial tensions properties and changes in flow behaviour assist the enhancement of oil recovery. Oil recovery can be improved by injecting gases and solvents or by stimulating their production by reservoir microflora in situ for reservoir repressurization and carbonate rock dissolution. The role of microbial surfactants in oil mobilization and that of biopolymers in oil-depleted zones for selective plugging have been delineated. The uses of solvents and organic acids in MEOR have also been briefly reviewed. Some results of laboratory studies are discussed. However due to accumulated toxic metabolites causing growth inhibition, poor yield of metabolic products of useful microbes and longer incubation time, the MEOR potential has not been fully realized. A complete assessment and evaluation of MEOR from an engineering standpoint based on performance, economics and applicability is required to further improve the efficiency of the process Thus, this review attempts to address the methods of oil recovery, MEOR past and recent trends and its future prospect.