MMT, Reach Subsea Invest in New Underwater Survey Technology
MMT Sweden AB and Reach Subsea ASA have jointly invested in developing a new special underwater tool for seabed mapping and pipeline inspection with the Norwegian ROV manufacturer Kystdesign AS. The potential market for pipeline inspection and survey in the North Sea is 2 Billion NOK yearly.
This new remotely operated vehicle (ROV), called Surveyor Interceptor, has the innovative shape, powerful propulsion and advanced instrumentation performs the work 4-8 times faster than existing Work Class ROVs. The umbilical and handling system yields up to 6 times better endurance than Autonomus Underwater Vehicles (AUV) The automatic tracking and station holding system delivers unsurpassed stability.
“This machine has a punch I could never have dreamt of. Together with the high precision instruments we can map at a quality not ever achieved before at reasonable cost,” says Ola Oskarsson Founder MMT Sweden AB.
“I am very pleased with the team and the effort resulting in this fantastic machine. Looking forward to present this extreme surveyor to the market,” says Jostein Alendal CEO Reach Subsea ASA.
Gassco operates the Norwegian gas transportation system, embracing nearly 8000 km of large diameter pipelines.
“We welcome this new technology and believe this will provide high quality in pipeline inspection and cost effective solutions to manage our assets,” says vice president in Gassco’s transport network department, Kristin Kinn Kaste.
The ROV is designed to carry survey instrumentation to perform Pipe line inspection, Route Surveys, Subsea Installation surveys and Environmental surveys down to 2.000 m water depth. By combining a hydrodynamic favorable hull, thin umbilical and extreme propulsion with the latest state of the art sensors the vehicle is intended to deliver, never before ultra high-resolution data at a substantial lower cost per km.
The offshore testing is performed in the Haugesund area in Norway with economic support from Gassco AS. The ROV is onboard MV Edda Fonn and manned by Survey specialists from MMT Sweden and ROV specialists from Reach Subsea and Kystdesign.
The tests are covering Launch & Recovery, Maneuvering, Velocity, Automatic pipe tracking and Survey systems.
Great emphasis is put to high resolution and accuracy. To achieve this the ROV is equipped with an onboard inverted USBL from Sonardyne doubled by normal Kongsberg Hipap transponders. This will increase accuracy and ensure redundancy. Also the positioning is supported by 2 INS systems and a DVL. The test of station holding, line running and tracking have given outstanding results.
The thruster management routines by Kystdesign have shown to be extremely reliable and precise.
The ROV propulsion has allowed MMT to reach speeds well over 6 knots with auxiliary power intact. The driveline will be adjusted after finishing the trials to ensure stability and power management up to 8 knots. MMT believes this is a world record for a ROV.
The Multibeam system delivers 40 Hz ping up to 20 m above seafloor. This together with the 800 beams ensures dense point coverage, even at high speed. To improve top of pipe accuracy and ovality measurements a 25 Hz triangulating laser system from Cathx Ocean covers the central 5 m of the survey corridor delivering mm accuracy measurements.
Three photomosaicing cameras are synchronized with powerful strobe lights, taking 3d, Stereo and geocorrected photos of the pipe to produce high resulotion GIS data of pipe status and possible third party intervention. The exposure time is very short <5 milliseconds to avoid motion blur and ensure crisp color seafloor imagery. This is also a very valuable tool for environmental investigations and geohabitat classification. The quality of these systems are approximately 8-10 times that of standard HD video with georeferenced frames. The systems detail and mosaicking capacity is astonishing and a huge improvement over standard video.
All in all, the results, data quality and performance are within or over expectation. Some driveline adjustments and time tagging issues remains. The Surveyor will be ready for work from March 2015.
Press release; Image: MMT