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Sonardyne, Oceaneering Demonstrate ROV Capabilities in U.S. Gulf

A recent trials partnership between Sonardyne International Ltd. and Oceaneering International, Inc. has resulted in the development of a Fly-By-Wire (FBW) system for ROV (Remotely Operated Vehicle) control in any water depth, allowing the vehicle to hold station indefinitely and navigate to real-world coordinates automatically.

A Sonardyne SPRINT system was installed on one of Oceaneering’s Maxximum ROVs and integrated with a Sonardyne Ranger 2 Ultra Short Baseline (USBL) system for acoustic aiding of the Inertial Navigation System (INS). The trials took place in the Gulf of Mexico in water depths of 3,057 metres (10,030 ft) and results showed that continuous hovering of the ROV in mid-water beyond Doppler Velocity Log (DVL) range was possible, as well as automatic navigation to waypoints.

The majority of ROV navigation systems utilize an Attitude and Heading Reference System (AHRS) and DVL to provide a relative or dead reckoned position. These systems are subject to time and distance based position errors and only operate close to the seabed, meaning mid-water operations are conducted via manual control so real world or relative coordinates cannot be easily used by the ROV pilot. To address these limitations, Sonardyne and Oceaneering have developed a novel navigation and control system solution utilising the dual output of INS and AHRS data from SPRINT to provide ROV Dynamic Positioning (DP) in all water depths with capabilities beyond current state-of-the-art, without affecting reliability or ease of use.

The system has two methods of ROV control: ‘Navigation’ and ‘Passthru’. In ‘Navigation’ mode, the ROV control system uses INS positioning optimised for DP with real-world position, velocity and attitude data at high output rates. This speeds up ROV operations by improving vehicle control precision, automating station keeping and delivering FBW capability. ‘Navigation’ mode is available continuously in all water depths when USBL data is available. If the INS solution should become degraded or is unavailable, the system automatically reverts to ‘Passthru’ mode. ‘Passthru’ mode is a dead reckoned solution using self contained AHRS data that is inherently robust and reliable when combined with DVL data.

The results of the trial showed that continuous hovering of the ROV in mid-water beyond DVL range was possible, as well as automatic navigation to waypoints. When the ROV was in DVL range of the seabed the ‘Navigation’ mode performed equally as well as the ‘Passthru’ mode but with the added benefit of real-world referenced positioning data from the USBL system. The faster update rate (20 Hz, compared to the 5 Hz rate of the DVL) has the potential to refine vehicle control precision.

Commenting on the development, Mark Carter, Business Development Manager for Inertial Systems at Sonardyne said, “Fly-By-Wire ROV control using real-world coordinates significantly improves operational efficiency compared to relative-only positioning methods. Faster navigation updates, automatic registering of waypoints and indefinite mid-water station keeping speed up ROV operations and ultimately save ROV and vessel time.”

Mark Philip, ROV Technology Manager at Oceaneering stated that, “Autonomous flight control is an increasingly important feature for ROVs. Oceaneering’s Fly-By-Wire system has greatly enhanced the efficiency of the service we provide to our customers since its introduction several years ago. The integration of the SPRINT inertial navigation system further enhances this capability by providing hands-free hovering and navigation throughout the entire water column. We place high importance on ease of operation and redundancy and are confident that our collaboration with Sonardyne satisfies these requirements.”

Sonardyne, Oceaneering Demonstrate ROV Capabilities in U.S. Gulf| Offshore Energy Today.

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Sonardyne Supplies BOP Control System to Noble’s Drillship (USA)

Sonardyne Supplies BOP Control System to Noble’s Drillship (USA)

Sonardyne International Ltd. has been awarded a contract by Noble Corporation to supply a Wireless Acoustic Emergency BOP Control System for its new deepwater drillship. The Noble Globetrotter II is the fifth Noble new-build vessel, along with other existing rigs, to be equipped with Sonardyne’s safety critical acoustic technology, providing reliable through-water wireless communications, positioning and BOP control in an emergency situation.

The Noble Globetrotter II is of similar design to its sister vessel, the Noble Globetrotter I. The vessel is due to begin work in the Gulf of Mexico in the second half of 2013.

Noble Corporation is one of the largest offshore drilling contractors in the world and operates a worldwide fleet of 79 rigs and drillships. The Noble Globetrotter II is currently en route to the Netherlands for tower and drilling system installation and once complete, will be capable of drilling in water depths up to 10,000ft. The vessel is due to begin work in the Gulf of Mexico in the second half of 2013 on long-term contract to Shell.

In the event of loss of normal communications with a BOP stack, Sonardyne’s self-contained, high security acoustic command and control backup system is used to execute emergency shutdown and riser disconnect procedures. The digital wideband acoustic signal technology incorporated into the supplied system has been proven to offer reliable performance in a well blow-out scenario despite intense noise pollution from a ruptured wellhead that would have severely limited the performance of an analogue acoustic BOP system.

“We have previously installed Sonardyne BOP control systems on several other Noble rigs so we’re delighted to be able to continue providing them with the critical positioning and control solutions they need,” said Ted Kenny, Business Development Manager of Subsea Control Systems at Sonardyne. “As the only provider with acoustic systems that are field-proven in the immediate vicinity of a major subsea blowout, we have the technology and in-depth knowledge to support Noble as it continues with its deep water exploration activities. The redundancy of the equipment chosen for the Noble Globetrotter II means that they will be able to reliably communicate with the BOP from either the rig or remotely from a standby vessel if the need ever arises.”

Subsea World News – Sonardyne Supplies BOP Control System to Noble’s Drillship (USA).

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