Abstract: In order to solve the decreasing of layering water injection rate of wells due to their casing damage in Shengtuo Oilfield, techniques of layering injection for patching and plugging section, sealing channeling in washable well and wells with slim hole have been studied. According to comprehensive analysis of wellbore environment, production parameters and operation, layering water injection tools suitable for different well conditions were developed and the measurement–adjustment techniques for water injection wells with slim hole were studied by simulation as well as other methods in the design and materials optimization, and tool performance improvement. A series of techniques for layering water injection of wells in complex well conditions was thereby formed. These layering water injection techniques have been applied in 59 wells with casing damage in Shengtuo oilfield with 65 water injection intervals increased, and water-drive controlling reserves of 477.9×10⁴ t recovered. Through the application of these techniques, multi-stage layering injection was realized. The research results could improve the benefit of water injection development in Shengtuo oilfield and provide reference in the commercial development of water flooding reservoir.