This study investigates the potential of enhancing oil recovery from a Middle East heavy oil field via hot water injection followed by injection of a chemical surfactant and/or a biosurfactant produced by a Bacillus s...This study investigates the potential of enhancing oil recovery from a Middle East heavy oil field via hot water injection followed by injection of a chemical surfactant and/or a biosurfactant produced by a Bacillus subtilis strain which was isolated from oil-contaminated soil.The results reveal that the biosurfactant and the chemical surfactant reduced the residual oil saturation after a hot water flood.Moreover,it was found that the performance of the biosurfactant increased by mixing it with the chemical surfactant.It is expected that the structure of the biosurfactant used in this study was changed when mixed with the chemical surfactant as a probable synergetic effect of biosurfactant-chemical surfactants was observed on enhancing oil recovery,when used as a mixture,rather than alone.This work proved that it is more feasible to inject the biosurfactant as a blend with the chemical surfactant,at the tertiary recovery stage.This might be attributed to the fact that in the secondary mode,improvement of the macroscopic sweep efficiency is important,whereas in the tertiary recovery mode,the microscopic sweep efficiency matters mainly and it is improved by the biosurfactantchemical surfactant mixture.Also as evidenced by this study,the biosurfactant worked better than the chemical surfactant in reducing the residual heavy oil saturation after a hot water flood.展开更多
WO_3 oxides with relatively high phonon energy and different concentrations were introduced into the Nd^(3+)-doped tellurite-based glasses of Te O_2-Zn O-Na_2 O to improve the 1.32 μm band fluorescence emission. The ...WO_3 oxides with relatively high phonon energy and different concentrations were introduced into the Nd^(3+)-doped tellurite-based glasses of Te O_2-Zn O-Na_2 O to improve the 1.32 μm band fluorescence emission. The absorption spectra,Raman spectra,1.32 μm band fluorescence spectra and differential scanning calorimeter(DSC) curves were measured,together with the Judd-Ofelt intensity parameters,stimulated emission and gain parameters were calculated to evaluate the effects of WO_3 amount on the glass structure and spectroscopic properties of 1.32 μm band fluorescence. It is shown that the introduction of an appropriate amount of WO_3 oxide can effectively improve the 1.32 μm band fluorescence intensity through the enhanced multi-phonon relaxation(MPR) processes between the excited levels of Nd^(3+). The results indicate that the prepared Nd^(3+)-doped tellurite glass with an appropriate amount of WO_3 oxide is a potential gain medium applied for the O-band broad and high-gain fiber amplifier.展开更多
基金Majesty Research Fund (SR/SCI/BIOL/08/01),Sultan Qaboos University,Oman and the Petroleum Development of Oman (CR/SCI/BIOL/07/02) for the research grants
文摘This study investigates the potential of enhancing oil recovery from a Middle East heavy oil field via hot water injection followed by injection of a chemical surfactant and/or a biosurfactant produced by a Bacillus subtilis strain which was isolated from oil-contaminated soil.The results reveal that the biosurfactant and the chemical surfactant reduced the residual oil saturation after a hot water flood.Moreover,it was found that the performance of the biosurfactant increased by mixing it with the chemical surfactant.It is expected that the structure of the biosurfactant used in this study was changed when mixed with the chemical surfactant as a probable synergetic effect of biosurfactant-chemical surfactants was observed on enhancing oil recovery,when used as a mixture,rather than alone.This work proved that it is more feasible to inject the biosurfactant as a blend with the chemical surfactant,at the tertiary recovery stage.This might be attributed to the fact that in the secondary mode,improvement of the macroscopic sweep efficiency is important,whereas in the tertiary recovery mode,the microscopic sweep efficiency matters mainly and it is improved by the biosurfactantchemical surfactant mixture.Also as evidenced by this study,the biosurfactant worked better than the chemical surfactant in reducing the residual heavy oil saturation after a hot water flood.
基金supported by the National Natural Science Foundation of China(No.61178063)the Natural Science Foundation of Ningbo City(No.2016A610061)+1 种基金the K.C.Wong Magna FundHu Lan Outstanding Doctoral Fund in Ningbo University
文摘WO_3 oxides with relatively high phonon energy and different concentrations were introduced into the Nd^(3+)-doped tellurite-based glasses of Te O_2-Zn O-Na_2 O to improve the 1.32 μm band fluorescence emission. The absorption spectra,Raman spectra,1.32 μm band fluorescence spectra and differential scanning calorimeter(DSC) curves were measured,together with the Judd-Ofelt intensity parameters,stimulated emission and gain parameters were calculated to evaluate the effects of WO_3 amount on the glass structure and spectroscopic properties of 1.32 μm band fluorescence. It is shown that the introduction of an appropriate amount of WO_3 oxide can effectively improve the 1.32 μm band fluorescence intensity through the enhanced multi-phonon relaxation(MPR) processes between the excited levels of Nd^(3+). The results indicate that the prepared Nd^(3+)-doped tellurite glass with an appropriate amount of WO_3 oxide is a potential gain medium applied for the O-band broad and high-gain fiber amplifier.
