Patent ID: 6422315
Filing Date: 2002-07-23
Classification: E21B

Abstract:
A control system for controlling drilling apparatus during subsea drilling operations during subsea retrieval of a subsea pod container containing apparatus for controlling the subsea drilling operations, the control system comprisinga first subsea pod container containing apparatus for controlling the subsea drilling operations, a second subsea pod container containing apparatus for controlling the subsea drilling operations, a third subsea pod container containing apparatus for controlling the subsea drilling operations, activation apparatus for activating a chosen one of the subsea pod container's apparatus for controlling the subsea drilling operations and maintenance apparatus for maintaining the two subsea pod containers other than the chosen one in a standby mode so that triple redundancy of control of the subsea drilling operations is provided, selection apparatus for selecting one of the subsea pod containers other than the chosen one from the two subsea pod containers maintained in standby mode in the event of a failure of the apparatus in the chosen subsea pod container for controlling the subsea drilling, and standby pod activating apparatus for activating a subsea pod container which was initially in standby mode for controlling the subsea drilling operations, so that the subsea drilling operations are not interrupted during retrieval of the chosen pod whose apparatus for controlling the subsea drilling operations has failed.