HOUSTON – Alan Duncan, managing director of InterMoor UK, presented findings from a recent Inter-M Pulse field trial in the North Sea at the Offshore Technology Conference.
Developed by InterMoor, in conjunction with sister company, Pulse Structural Monitoring, the Inter-M Pulse is a long-term mooring connector that has the capability to monitor and track the in situ tension of each mooring line and transmit tension data acoustically to the topside control room.
With the introduction of various sensors, the Inter-M Pulse can also detail inclination of the mooring line. Additional features include: full history of the mooring line, acoustic data transmission, on-demand data upload, and a traffic light alarm system.
To ensure the technology of the Inter-M Pulse, a 76 mm (800T Minimum Break Load (MBL) unit was installed over the stern roller of an AHV for the Ocean Nomad semisubmersible at Everest 22/10a in the North Sea in winter 2012 for a six-month drilling campaign. The unit deployed was designed for use on all offshore units. The field trial mooring system consisted of a combination chain and fiber makeup with the unit installation located at the fiber and shackle connection.
During the sea trial there were typical sea states of around 39 ft (12 m). At all times the Inter-M Pulse was able to send accurate line tensions and inclination readings to the control room on board the rig. After a successful installation, the unit was immediately operational and feeding line tensions and inclination readings to the surface.
The data was sent back to the topside system via the acoustic data link once a minute for several hours a day. The sea trial proved that the system will communicate in a range of sea states. The readings have since been verified and documented.
Duncan said: “In addition to its valuable use in permanent and drilling moorings worldwide, the Inter-M Pulse could prove crucial for operators as US regulations demand that rig managers and production unit operators report on the status of their mooring systems after a hurricane. This technology allows full calibration on mooring chains without losing valuable rig time.
“During a storm the Inter-M Pulse is capable of feeding live data from the mooring chains up to the control room, and in the aftermath uploading and analyzing the findings to determine the storm’s impact and verify the mooring system’s dynamics.”