The improvement and application of hydraulic casing centralizer for well cementating in horizontal wells

The structure of hydraulic centralizer is improved, and relevant ground experiments are carried out in regard of the problems of influence on annular open area after bows are opened, sealing failure due to secondary piston motion during application of hydraulic casing centralizer in horizontal wells. A ball seat supporting the hydraulic centralizer is developed. After a hydraulic centralizer is lowered in position, a ball is put in position to start up the hydraulic centralizer before cycle operation. In this way, boreholes can be cleaned thoroughly, well cementation quality is enhanced, and casing centralization process is improved. The improved hydraulic centralizer is applied to unconventional horizontal wells for 4 well times, with 32 hydraulic centralizers applied to each well in average, and well cementation and fracturing processes are both free of sealing failure. Well cementation is in sound quality, indicating that the improved hydraulic centralizer is more suitable for well cementation for unconventional horizontal wells.