Petroleum sulfonate is one of the most important surfactants used in surfactant flooding for enhanced oil recovery, which is mainly obtained by treating high-boiling petroleum fractions in a stirred tank reactor(STR) ...Petroleum sulfonate is one of the most important surfactants used in surfactant flooding for enhanced oil recovery, which is mainly obtained by treating high-boiling petroleum fractions in a stirred tank reactor(STR) or in a fallingfilm reactor(FFR). The synthesis of petroleum sulfonate with ultra-low interfacial tension from viscous petroleum fractions was carried out in a rotating packed bed(RPB) reactor using dilute liquid sulfur trioxide as the sulfonating agent in this study. The effects of various experimental conditions on components content and oil-water interfacial tension(IFT) were investigated. Under the optimum conditions, the active matter content could reach up to 50.3% and the IFT could be equal to 4.7×10-3 m N/m. Compared with the traditional reactor, the active matter content is by 14.12% higher in the RPB as compared to that obtained in the STR. The uneven change of the test oil droplets during the IFT measurement was also discussed. The increase of heavy components content not only can eliminate the contraction phenomenon, but also can reduce the IFT to a minimum. This can be conducive to explaining the reason for producing IFT and the preparation of proper formulations for practical application.展开更多
In this paper, as far as the ASP flooding in the pilot area of Daqing oilfield is concerned, the effect of apparent viscosity of ASP solution on enhanced oil recovery have been studied by comparison of experiments on ...In this paper, as far as the ASP flooding in the pilot area of Daqing oilfield is concerned, the effect of apparent viscosity of ASP solution on enhanced oil recovery have been studied by comparison of experiments on artificial heterogeneous cores with on natural cores. The results showed that the decrease in the concentration of alkali could increase the apparent viscosity of ASP solutions, namely, the apparent viscosity increased and the IFT couldn’t get ultra low, and the oil recovery efficiency by ASP solution with a reasonably lower concentration of alkali was not less than that with a higher concentration of alkali and ultra low IFT. The experiments with models having impermeable interlayers between adjacent layers, and by means of “co-injection and separate production” showed that the ASP solution with a higher viscosity and a lower alkali concentration was more beneficial to starting-up medium and low permeability layers and enhancing total oil recovery. Therefore, to heterogeneous reservoir, as factors of affecting oil recovery, the apparent viscosity may be more important than the ultralow IFT. Furthermore, on the premise that the concentration of surfactant and the concentration of polymer keep constant, ASP flooding with low alkali concentration not only enlarges the selectable range of surfactants and decreases the cost of ASP flooding, but also solves the problem of alkali scales. Finally, a dynamic absorption experiment was performed with a 05 meter long linked-up natural core to determine alkali wastage in formation. The result being accord with the application case in the pilot confirmed that it was not necessary to add the alkali too much in ASP flooding from a new direction.展开更多
基金supported by Project of the National Twelfth Five-Year Research Program of China (Grants. 2014BAE03B02)
文摘Petroleum sulfonate is one of the most important surfactants used in surfactant flooding for enhanced oil recovery, which is mainly obtained by treating high-boiling petroleum fractions in a stirred tank reactor(STR) or in a fallingfilm reactor(FFR). The synthesis of petroleum sulfonate with ultra-low interfacial tension from viscous petroleum fractions was carried out in a rotating packed bed(RPB) reactor using dilute liquid sulfur trioxide as the sulfonating agent in this study. The effects of various experimental conditions on components content and oil-water interfacial tension(IFT) were investigated. Under the optimum conditions, the active matter content could reach up to 50.3% and the IFT could be equal to 4.7×10-3 m N/m. Compared with the traditional reactor, the active matter content is by 14.12% higher in the RPB as compared to that obtained in the STR. The uneven change of the test oil droplets during the IFT measurement was also discussed. The increase of heavy components content not only can eliminate the contraction phenomenon, but also can reduce the IFT to a minimum. This can be conducive to explaining the reason for producing IFT and the preparation of proper formulations for practical application.
文摘In this paper, as far as the ASP flooding in the pilot area of Daqing oilfield is concerned, the effect of apparent viscosity of ASP solution on enhanced oil recovery have been studied by comparison of experiments on artificial heterogeneous cores with on natural cores. The results showed that the decrease in the concentration of alkali could increase the apparent viscosity of ASP solutions, namely, the apparent viscosity increased and the IFT couldn’t get ultra low, and the oil recovery efficiency by ASP solution with a reasonably lower concentration of alkali was not less than that with a higher concentration of alkali and ultra low IFT. The experiments with models having impermeable interlayers between adjacent layers, and by means of “co-injection and separate production” showed that the ASP solution with a higher viscosity and a lower alkali concentration was more beneficial to starting-up medium and low permeability layers and enhancing total oil recovery. Therefore, to heterogeneous reservoir, as factors of affecting oil recovery, the apparent viscosity may be more important than the ultralow IFT. Furthermore, on the premise that the concentration of surfactant and the concentration of polymer keep constant, ASP flooding with low alkali concentration not only enlarges the selectable range of surfactants and decreases the cost of ASP flooding, but also solves the problem of alkali scales. Finally, a dynamic absorption experiment was performed with a 05 meter long linked-up natural core to determine alkali wastage in formation. The result being accord with the application case in the pilot confirmed that it was not necessary to add the alkali too much in ASP flooding from a new direction.
