Abstract: In most of the production wells in Bohai Oilfield, large section of sand control and general injection-production way are mainly used, and the problems of the water channeling among different sand control intervals can be solved by using wellbore tools. However, the situation of water channeling within individual layers cannot be solved. The water plugging by chemical method is an effective technique to solve this problem. Therefore, study has been conducted on water plugging technology with foam system, and furthermore put the foam system into field test successfully in well XX in Bohai Oilfield. The oil production rate has been increased greatly after application. This technique shows a great application prospective in the future.