84 “Eventually, we wondered why can’t we just drop the nodes off the side of the vessel? We envisioned making a node that could steer itself to control its own heading and pitch throughout descent, and then ascend once it finished gathering data. We did some calculations, realised it was possible, and filed a successful application for EU funding support.” Through that funding, iDROP has engineered its Oceanid autonomous ocean-bottom node, a 25-30 kg, torpedoshaped system (not including a ballast attachment weighing a few kilograms, installed just before deployment and descent) integrating a battery that powers up to 180 days of data recording, assuming a 2 ms recording frequency. Initial near-shore trials of Oceanid units have been carried out, thanks to iDROP’s proximity to the Oslo fjord, and the test sites, test vessels and 500 m sea depths there. In addition to EU funding, the system’s ongoing development and trials are supported by a consortium composed of ExxonMobil, HESS and Woodside Energy. Oceanid is designed to be positivelybuoyant and without thrusters. Following deployment, it descends under the mass of the aforementioned external ballast attachment, while steering itself autonomously to a specified survey point on the seafloor (thanks to its hydrodynamic cylindrical shape and three symmetrical, electromechanical, servo-actuated fins about its body). Upon arriving at the seafloor, the Oceanid deploys its seismic sensor package, as well as a proprietary soil-skirt mechanism that couples it securely to the seafloor. Once it has gathered the requisite data, based on its programmed mission plan, the autonomous node retracts its coupling system and releases its ballast to float up to the surface (potentially steering itself again to a recovery location predefined at the ocean surface). “This approach means we reserve 95% of battery energy for data gathering and recording, with maybe 5% used in descent, ascent, and acoustic modem communications between nodes and to the survey vessel. It keeps the solution very efficient,” Tjøm says. “We plan to deploy swarms of nine Oceanids at a time, positioning them in a 3x3 matrix on the seafloor to survey large areas, and through their acoustic modems the nodes can transmit and receive timeof-flight data among themselves for precise navigation and guidance, without needing to rely on USBL or traditional LBL positioning systems.” Similarly, Italian multinational oilfield services company Saipem first conceived of a resident ROV solution in 2009, as a means of improving underwater inspection and maintenance operations. By having a ROV working in residence, rather than having to be deployed, controlled and retrieved by a crewed vessel, underwater operations could be performed with greatly reduced costs, carbon emissions and risk to personnel. “The technology available at the time was not sufficiently mature,” recounts Mauro Piasere, COO of robotics and industrialised solutions at Saipem. In 2016, however, Saipem revived the concept and started the Hydrone investment programme, finalising the first prototype of its Hydrone-R resident UUV solution by the end of 2019. Around that time, Piasere adds, Equinor awarded Saipem the first resident uncrewed vehicle service contract in the energy sector. “Between 2020 and 2022, the vehicle was customised to meet the specific needs of this first application and final tests were performed. Hydrone-R was accepted by Equinor in late 2022 and launched into the water in June 2023,” he says. “After a familiarisation period, the drone was recovered for maintenance in November 2023, and relaunched into the water at the end of May 2024.” Today, the Hydrone-R ROV/AUV hybrid vehicle is a system typically weighing 3800 kg in air, and measuring 3000 mm long, 2100 mm tall and 1800 m wide, while capable of operating down to depths of 3000 m. In addition to integrating cameras and sonars for its AI-based navigationcontrol system, the UUV has served in operations over the past 12 months in which it remained connected to a docking station, which provided a data link for real-time data streaming and a power line for battery charging. Through this capability, the system achieved an uninterrupted dive of 167 days in 2024, with Saipem estimating that up to 12 months of uninterrupted February/March 2025 | Uncrewed Systems Technology The Hydrone-R weighs 3800 kg in air, integrates cameras and sonars for its AI-based navigationcontrol system, and achieved a 167-day uninterrupted dive in 2024 (Image courtesy of Saipem)
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