Abstract: In order to overcome the problems of Russian mobile vibrators which include starting difficulties and limited running time,a set of mobile vibratory cementing devices suitable for ϕ139.7 mm casing was formed by optimizing the structures of eccentric blocks of vibrators based on mechanical analysis and matching surface electronic control system.They were formed after the development of downhole vibrators and simplification of pressure balance mechanism.Surface tests indicated that the mobile vibratory cementing device applicable to the well section with deviation angle less than 50° started easily and might work for a long time.Field tests indicated that the cementing quality of vibration cementing intervals were significantly improved by using the mobile vibratory cementing device for test wells.Compared with the same intervals in the adjacent wells without using vibration cementing,the high quality rate of the first interface and qualification rate of the second interface were improved by 17.5 and 45.0 per cent respectively.The research showed that self-developed mobile vibratory cementing device could overcome the defects of Russian mobile vibrators,and could be suitable for a domestic casing program and thus effectively improve the cementation quality of the first and second interfaces.