Keywords: 
• polymer /
• separate layer /
• injection /
• oil displacement efficiency /

Abstract: Introduced the technology of selective injecting polymer into individual zones,which is mainly used to solve the interzone contradictions resulted from the general injection mode and the shear degradation problems occurred when using the conventional technology of selective injecting water into individual zones to inject polymer. The technology satisfies the demands of selective injection of polymer and well cleanout rnainly through the selective injection tubing string of dual tube, like this, it can both avold or reduce maximally the damage of the shear degradation and the iron ions caused when the polymer flows through the nozzle, and can let the casings above the perforation not bear against high pressure, in the mean time, the polymer with different molecular weight and different concentration can be injected into individual zones quantitatively. The amount of selective injection can he controlled on the surface with simple, audio-visual and accurate metering, it both reduces the labor strength of the conventional multi-zone testing, and can better solve the interzone interference problem resulted from the general injection mode. The application feasibility and development prospect of the technology was also demonstrated by the field test.