Laboratory Investigation of Indigenous Consortia TERIJ-188 for Incremental Oil Recovery

Bacterial Profile modification is an efficient process which brings the alteration in permeability of the porous media of the reservoir by selective plugging which eventually recover the residual oil. It is an advantageous and feasible method for residual oil recovery from high permeability zones of the reservoir. In this study, indigenous bacterial consortia, TERIJ-188 was developed from Gujarat oil fields. TERIJ-188 was identified as Thermoanaerobacter sp., Thermoanaerobacter brockii, Thermoanaerobacter italicus, Thermoanaerobacter mathranii, Thermoanaerobacter thermocopriae. The novelty of consortia was that it produces biomass (850 mg l-1), bio-surfactant (500 mg l-1), and volatile fatty acids (495 mg l-1) at 70°C in the span of 10 days, which are adequate to alter the permeability and sweep efficiency of high permeability zones facilitating the displacement of oil. The biosurfactant was analyzed for its functional group by FTIR and NMR techniques which indicate the presence of C-N bond, aldehydes, triacylglycerols. TERIJ-188 showed an effective reduction in permeability at residual oil saturation from 28.3 to 11.3 mD and 19.2% incremental oil recovery in a core flood assay. Pathogenicity test suggested that TERIJ-188 is non-toxic, non-virulent and safe for field implementation

Instigation of indigenous thermophilic bacterial consortia for enhanced oil recovery from high temperature oil reservoirs.

The purpose of the study involves the development of an anaerobic, thermophilic microbial consortium TERIK from the high temperature reservoir of Gujarat for enhance oil recovery. To isolate indigenous microbial consortia, anaerobic baltch media were prepared and inoculated with the formation water; incubated at 65°C for 10 days. Further, the microbial metabolites were analyzed by gas chromatography, FTIR and surface tension. The efficiency of isolated consortia towards enhancing oil recovery was analyzed through core flood assay. The novelty of studied consortia was that, it produces biomass (600 mg/l), bio-surfactant (325 mg/l), and volatile fatty acids (250 mg/l) at 65°C in the span of 10 days, that are adequate to alter the surface tension (70 to 34 mNm -1) and sweep efficiency of zones facilitating the displacement of oil. TERIK was identified as Clostridium sp. The FTIR spectra of biosurfactant indicate the presence of N-H stretch, amides and polysaccharide. A core flooding assay was designed to explore the potential of TERIK towards enhancing oil recovery. The results showed an effective reduction in permeability at residual oil saturation from 2.14 ± 0.1 to 1.39 ± 0.05 mD and 19% incremental oil recovery