Abstract: In view of chromatographic separation problem of chemical displacing agent and suitable scale models for evaluation of effect of alkali-surfactant-polymer (ASP) flooding,potentiometric titration method was used separately for quantitative determination of alkali and surfactant mass concentration of the effluen, while for quantitative determination of polymer mass concentration of the effluent,cadmium iodide and starch method was used.At the conditions of reservoir temperature of 69 ℃,chromatographic separation of the length scales sandpack of 30,100 and 240 cm on ASP flooding was separately investigated.The results showed that,with the scales of sandpack ranging from 30 to 240 cm,the normalized breakthrough time of polymer,alkali and surfactant is stepwise increasing correspondingly.With the scales of sandpack ranging from 30 to 100 cm,all the migration lag coefficients between the three components display rather big difference;the chromatographic separation is serious,but the degree of chromatographic separation does not increase.With the scales of sandpack ranging from 100 to 240 cm,there is a trend of decline of the degree of chromatographic separation.The model scale for the evaluation of effect of ASP flooding in the laboratory as well as in the oilfield site should be more than 100 cm.

Key words: ASP flooding;chromatographic separation;length scale;normalized breakthrough time;migration lag coefficient