Abstract: In order to effectively utilize offshore well slots and produce the remaining oil, the sidetracking technology was used on a shut-down well named Hai H1 in Bohai Oilfield due to sanding. In view of the high cost of drilling and the poor economic returns for using conventional sidetracking, the medium and short radius sidetracking technology was used by Well Hai H2 in order to reduce the footage and drilling cost. At the same time, considering the risk of encountering high water-flooded layers and mudstone interlayers after sidetracking, Well Hai H2 was designed to be a horizontal casing well. In the subsequent implementation, the drilling and completion operations went successfully, and a good result was obtained after production with low water content for long-term. The successful implementation of this well provides a technical approach to realizing economic and efficient sidetracking for the inefficient well in Bohai Oilfield.