High resolution structural inspection of flooded tunnel
RTS AS needed a reliable and efficient method for wirelessly monitoring and retrieving data, in real time, from subsea structures during seabed installations in oil and gas fields. The system had to provide real time heading, pitch, roll, depth, inclination and deflection information to the operator during installation. The system was based on an instrument frame containing a subsea logger and gyro with inclinometers and a battery pack. A set of high precision depth sensors were also installed in each corner of the structure and were used for deflection calculations. This information was required for precise positioning, leveling and regulation of the suction process during installation. All sensor data needed to be collected, time stamped and logged by the RTS subsea logger, and simultaneously transferred to the ship via acoustic link. To facilitate recovery of the system after the operations were completed, the Subsea Deflection Monitoring System (SDM) instrument frames also had to be equipped with an ROV recoverable bracket mount. Depending on the project, one or two identical systems would be installed on the structure; one as the primary system and the other as a backup system.
