Abstract: The logging data acquisition technology in the casing is different from conventional open hole logging. It is a logging data acquisition technology in the casing after the completion of the cementing operation. It can solve the problem of well logging data in the open hole well, ensure the safety of logging operation, and can also be used as the supplement of open hole logging. In recent years, the practice of logging through casing in Bohai Oilfield has proved that the logging data in casing well can meet the demand of development and adjustment wells. This technology is an effective method for logging data acquisition under complex well conditions, which is especially important for offshore oil fields. The application prospect is broad.