جستجوی مقالات مرتبط با کلیدواژه "interfacial tension reduction" در نشریات گروه "مهندسی شیمی، نفت و پلیمر"

Recently, nanoparticles of various types have been used in enhanced oil recovery (EOR) research studies. Their tiny size and unique structure made them potential additives to take part in fluid/fluid and fluid/rock interactions leading to increased recovery from depleted oil reservoirs. Among different nanoparticles, multi-walled carbon nanotubes, because of their functionalization and possibility of surface modification, an abundance of carbon sources and reasonable price have gained increased attention. In this work, a novel nano-complex has been synthesized by surface modification of functionalized multi-walled carbon nanotubes using cetyltrimethylammonium bromide (CTAB) surfactant and polyethylene glycol (PEG) polymer. The prepared nano-complex was then used as an EOR agent in a crude oil-low salinity seawater-dolomite system. The experimental results revealed profound reduction of IFT in the presence of the nano-complex where an IFT value of 0.5 mN/m at critical micelle concentration (CMC) of 60 ppm was recorded. Moreover, profound wettability alteration from oil-wet toward water-wet state and low adsorption of the nano-complex on dolomite surface further confirmed its applicability in EOR practices.

The most important mechanism of microbially enhanced oil recovery processes is changes in interfacial properties of fluid/fluid/rock affected by bacterial cells and their metabolites. In this study, two bacteria B.licheniformis and P.putida and three different sources of carbon were used. Results showed that due to the effect of carbon source on bacterial growth and also type and value of produced metabolites, changes in interfacial properties of fluid/fluid/rock is affected by used carbon source. The better growth of both bacteria occurred in a culture medium containing glucose. Pendant drop tensiometry, electrophoretic mobility measurement, interfacial dilational rheology and contact angle test were used to investigate the effect of cell structure and culture medium composition on interfacial tension reduction, emulsion stability, and wettability alteration mechanisms. The results of this section showed more potential of P.putida bacteria in surfactant production. Also, results showed that glucose is a better culture medium for B.licheniformis bacteria. Produced biosurfactants and bacterial culture of B.licheniformis bacteria in medium with glucose carbon source reduced surface tension and interfacial tension by 29.07% and 43.87%, respectively. Submerging thin section in glucose culture medium of B.licheniformis bacteria reduced the contact angle of water drop from 109.081 to 44.898°. In the case of P.putida bacteria, the oily and glucose culture media are respectively the effective media for influencing the fluid-fluid and fluid-rock interface. The produced biosurfactants and bacterial culture of P.putida bacteria in medium with olive oil carbon source reduced surface tension and interfacial tension by 36.4% and 27.1%, respectively. The contact angle of drop water was reduced from 109.081 to 54.050° in glucose culture medium of P.putida bacteria