关键词: 强碱三元复合驱,    ,  , 举升设备,    ,  结垢,   ,  电子探针,   ,  溶蚀

Abstract: Scaling phenomenon widely existing in the process of base ASP flooding will affected subsequent water flooding and lifting system adversely. The scale composition change and types in the lifting system and formation were studied and the scale statistics from lifting system, casting thin sections, SEM and electron probe analysis were used to determine the base ASP flooding. The results showed that the main scale types changed with the PV injection of base ASP flooding. In early injection stage, the scale was mainly carbonate scale containing a small amount of silica scale and organic matter. In the middle injection stage, the number component of three scales was same. In later injection stage, the scale was the same with early injection stage. Casting thinsection analysis showed that the scale form was “white clouds” and “brown cementation”. With part of the pores blocking, surface pore rate fell by 6.45% on average. The types of scale formation in the study area were mainly calcium scale and silicon scale, containing a small amount of barium/titanium scale and iron scale. Due to alkali dissolution, scaling phenomenon in formation and wellbore appeared frequently, so it was suggested that base ASP flooding should be replaced wit weak ASP flooding if it can achieve the same improving recovery rate.

Key words: Base ASP flooding,    ,  Lifting equipment,    , Scale,    ,  Electron probe,    ,  Dissolution