大庆原油与碱作用机理研究

 采用四组分分离法将大庆原油分离为饱和分、芳香分、胶质和沥青质，并用醇碱萃取法提取原油中的酸Ⅰ组分和酸Ⅱ组分。分别考察了各组分模拟油与水及碱体系的界面张力、界面剪切黏度，以及模拟油与碱长时间反应所形成的乳状液稳定性。结果表明，大庆原油中能降低油-水界面张力的主要活性组分是与碱反应较快的酸；对模拟油与碱体系形成的W/O型乳状液起稳定作用的主要组分是其中与碱反应较慢的、支链较多的大分子酸及酯类。大庆原油饱和分中存在着与碱发生慢反应的酯类。原油、原油组分模拟油与 碱反应初期，易形成O/W型乳状液，反应后期乳状液由O/W型向W/O型转变。醇碱萃取法只能萃取出与碱发生快速反应的酸组分，而不能将与碱反应较慢的相对分子质量较大的酸或酯类萃取出来。

INVESTIGATION IN THE REACTION OF DAQING CRUDE OIL WITH ALKALI

Saturation, aromatic, resin and asphaltene fractions were separated by four fraction separation method, and acid fractions (acid Ⅰand acid Ⅱ) were separated by ethanol-caustic solvent extraction from Daqing crude oil. Interfacial tensions, interfacial shear viscosity and stability of emulsion formed with model oil-lye or model oil-water systems for a long time were measured. Experimental results proved that the saponification compounds play important role in decreasing the interfacial tension between Daqing model oil and lye system, which formed by the acids with smaller relative molecular mass in oil with alkali in short time. For the emulsion of model oil and lye system the soap formed by slow reaction of the acid, the esters with larger average molecule mass and alkali were responsible for enhancing the stability of the emulsions. These compounds were in the saturate fraction from Daqing crude oil. In the earlier stage of the reaction of model oil with lye, the type of emulsion was O/W, and later the type of emulsions became W/O. Though by the method of ethanol-caustic solvent extraction the acid fractions in the crude oil were obtained, which fast reacted with alkali, the acid fractions in the crude oil, which slowly reacted with alkali, could not obtain.