SeeByte Ltd has successfully completed sea operations of its new SeeTrack Offshore automated inspection system on the Foinaven and Schiehallion oilfields, west of the Sheltand Islands. The purpose of the operations, which were funded by BP and supported by Subsea7, was to run SeeByte’s automated inspection system, comprising an advanced ROV DP system capable of keeping station relative to stationary or moving targets such as risers, baskets and manifolds whilst carrying out inspection tasks. Chris Button of BP’s Exploration and Production Technology Group stated that “BP recognised the potential benefits of this technology from an early stage of development. In the light of this successful field trial, we are confident that SeeTrack Offshore will be a powerful tool for subsea inspection and maintenance in the near future”. The SeeTrack Offshore ROV DP and Target Tracking modules are a simple retrofit, providing a turnkey system without modification to the ROV. Both modules have been used to operate observation- and work-class ROVs; they boast over 1000 hours in the water so far.
SeeTrack Offshore was installed on the ROV and dry tested in Invergordon Harbour before the ship sailed to the field. The system had not been interfaced with a Hercules-class vehicle before and so the control loops were auto-tuned in the field, taking fewer than seven in-water hours to achieve a stable hover. Hover performance proved to be exceptional, achieving tight position and depth control and heading control to within a degree. The SeeTrack Offshore system ran the ROV successfully through a variety of operations, such as manipulator work, IMR and target tracking; both the DP and Target Tracking modules were then used to inspect a working riser. The system was used to automatically inspect in two passes 75 meters of the chosen riser, 10 meters above the upper tether clamp, taking 25 minutes in total. The data quality was rated as ‘superb’ by the surveyors.
In order to guarantee this success, SeeByte engineers worked closely with the users to ensure ease of use. As a result the ROV pilots were able to learn to use the technology extremely quickly. Pilots, surveyors and supervisors were very impressed with the system throughout the operations, particularly the superb hover performance that allowed a significant increase in data quality and consistency.
The SeeTrack Offshore DP module provides an electronic joystick output, so it can be installed by plugging the ROV pilot’s joystick into a switch box. This allows pilot-selection between the pilot’s joystick and SeeTrack Offshore’s electronic joystick; the failsafe is to pilot control. A bottom-tracking Doppler is mounted on the vehicle and fed up to the surface via the ROV’s tether and the ROV’s own depth and heading sensor data is also fed into the SeeTrack Offshore surface unit.
In order to use the Target Tracking module, a forward-look sonar is also mounted on the vehicle and fed into SeeTrack Offshore. SeeTrack Offshore is compatible with most commonly-used sonar brands.
The level of automation offered by the ROV DP and Target Tracking modules reduces the amount of time required for operations and the smooth and accurate hover ensures that inspection photographs are right first time, every time.