|
Betaine-type surface active agent is typical of a class of amphoteric surfactants, have unique properties. However, due to technical price betaine surfactant in the variety and quality can not meet the requirements of the relevant areas, thus its synthetic and industrial applications, more and more attention. Betaine type surface active agent used in EOR reported rarely class surfactants having good foaming properties and foam stability characteristics, taking into account, there may be suitable for flooding surfactant bubbles. Synthesis a series the alkylamide sultaine, and discusses the synthesis process, the surface tension of crude oil / water interface, performance, and foam performance, preliminary exploration for the class of surfactant in EOR. As raw materials, with different carbon chain length of the fatty acid and N, N-dimethylpropanediamine, and after the condensation reaction of amidation, the four tertiary amine intermediates were prepared: 12-amidopropyl dimethyl amine (DAPDA), ten The four amide the dimethylamine (TAPDA), 16 amide the dimethylamine (HAPDA) and 18 amide propyl dimethyl amine (OAPDA). Fatty acid conversion was investigated indicators, focused on the reaction temperature, reaction time on the synthesis reaction. The results show that: the reaction temperature of 150 ° C, the reaction time 7h, fatty acid conversion rate of more than 94%. Secondly, the above four tertiary amine intermediate and 3 - chloro-2 - hydroxy propane sulfonate (Lab homemade) as raw material, after the quaternization reaction, the prepared four betaine type surface active agent: dodecamide the the sultaine (DAHSB), myristamide the sultaine (TAHSB), 16 amide the sultaine (HAHSB) and 18 amide sultaine (OAHSB). HAHSB synthesis, for example, to determine the optimum reaction conditions by orthogonal test results showed that: when using water as a solvent, the optimum reaction conditions, the reaction temperature is 85 ° C, reaction time 6h, tertiary amine and 3 - chloro -2 - hydroxy-propane sulfonate molar ratio of 1:1.1, material percentage of 30 wt% and a yield of 83.6%; isopropanol / water for the mixed solvent, the optimum reaction conditions, the reaction temperature of 80 ° C, reaction time 6h a tertiary amine with 3 - chloro-2 - hydroxy propane sulfonate mole ratio of 1:1.1, isopropanol and water in volume ratio of 1:2, 88.9% yield. By infrared spectroscopy, ultraviolet spectroscopy, nuclear magnetic resonance, mass spectrometry, and other methods to characterize the structure of the product. Against Daqing Oilfield conditions, studied the surface tension of the above four betaine surfactant, the critical micelle concentration. Explore of four betaine surfactant and oil / water interfacial tension minimum concentration and the dynamic value, alkalinity characteristics. Four betaine surfactant system interfacial tension stability were tested. The effects of four betaine foam properties of the surfactant system. Interfacial tension performance tests showed that the presence optimum surfactant concentration (0.1wt%) and alkali concentration (0.5wt%), under this condition of each surfactant system and oil / water interfacial tension can reach 10-Min 3mN / m magnitude. Foam performance tests show that the surfactant concentration 0.3wt%, the foam optimal performance as DAHSB the Foam Composite Index reached 117,117.
|