Abstract: Alkali-surfactant-polymer (ASP) flooding is of better effect for oil displacement than water flooding by EOR of over 20%. Because of the injection of alkali, the injection-production system by ASP flooding process is normally impacted by serious scaling of the wells, which is unfavorable for normal production of a field. This paper analyzes the representative scaling sample from ASP flooding in Daqing oil field. The result shows that the main components of the scaling are calcium and magnesium carbonates, silicate, pipeline corrosion product and organic matters, etc. and the scaling follows such regularities as: the carbonate content is gradually decreased with time in the same position of production well, but that of silicate is increased; the carbonate content is decreased, the silicate content is gradually increased from wellhead to wellbottom at the same time interval. The feasible suggestions are put forward on the basis of the scaling characteristics.

Key words: Daqing oil field, ASP flooding, production well, scaling, regularity