Abstract: Casing failure will bring great challenge to wellbore integrity, and the uncertainty of exploratory drilling pressure systems may lead to more serious well control risks. In order to meet the requirements of wellbore completion in subsequent drilling operations with casing failure, it is necessary to optimize the casing repair process. This paper analyzes the technical principle of casing repair, and introduces the optimization and practice of casing repair technology with an exploration well in Bohai Sea as an example. Finally, casing repair was successfully realized and the pressure test was qualified, and the first successful application of casing repair technology in exploration drilling in Bohai Sea was realized. This technology can provide an important reference for the integrity management of Bohai Sea exploration wells, and can be extended to other casing damage conditions.