For decades, subsea exploration has required a vessel to sail out to the asset carrying the crew and equipment required to examine what lies below. Resident autonomous underwater vehicles (AUVs) are reshaping the automation of offshore inspection by staying close to the infrastructure and returning to work on demand.
The result is a reduction in vessel support, though some basins and tasks will still require it.
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AUV testing in practice
Norwegian energy giant Equinor has been testing AUV technology. It acquired the Eelume S AUV in September 2025, following successful demonstrations in harsh subsea conditions. Equinor has a decade-long relationship with Norwegian technology company Eelume, and the acquisition represents a transition from early-stage financial support to full operational deployment.
Speaking to Offshore Technology, Equinor’s marine robotics head Jan Christian Torvestad explains that the acquisition of the AUV enables the company to build in-house experience with an emerging subsea technology.
Equinor has also been successfully testing the Hydrone-R in the Njord oil and gas field—an all-electric resident underwater intervention drone (UID), as part of a ten-year contract with Italian engineering company Saipem. Signed in 2019, the contract is worth around €40m ($44.5m) and includes the Hydrone-W work-class remote operating vehicle (ROV). It has set residency records with more than 280 docking missions across two deployments.
Saipem claims the deployment has gone beyond technology demonstration. Hydrone-R has been operational at Njord since 2023 and has accumulated more than 500 days of subsea residency, including a record 240 consecutive days on the seabed.
“Hydrone-R has demonstrated that the concept of a resident subsea drone has reached tangible commercial maturity,” says Adriano Mongini, Saipem’s Drilling and Sonsub chief operating officer. He adds that the system is operating as an industrial solution under a long-term contract with Equinor, demonstrating the viability of a new Life of Field (LoF) service model, based on robotic assets permanently available on the seabed.
Saipem claims that Hydrone-R has completed hundreds of vessel-free missions, including subsea inspections, autonomous surveys, troubleshooting and light intervention. A vessel is typically required for launch and recovery every six to eight months, while routine LoF activities can be carried out without a dedicated support vessel.
The Hydrone-R achieved a longer subsea residence period than expected, says Torvestad, but he cautions that deployment is still in an experimental phase. Equinor selects the most suitable and cost-effective tool for each task, and inspection vessels are still required for more complex work.
Equinor’s approach represents an emerging model, reshaping vessel demand rather than eliminating it. Autonomous systems take on regular inspection, while vessels continue with recovery, intervention and construction.
Why resident AUVs are now viable options
Alongside the emergence of new AUV capabilities, the development of subsea infrastructure is enabling docking, data transfer, battery charging and shore-based supervision. Technologies such as advanced sensors, connections to predictive analytics and digital twins are moving the technology forward.
GlobalData’s January 2026 report, ‘Robotics in Oil and Gas‘, identifies these developments as part of a wider automation shift. Across industries, it forecasts that the global robotics market will grow from $90.2bn in 2024 to $205.5bn in 2030.
“While challenges remain, the integration of robotics with digital twins, edge intelligence and predictive analytics is accelerating,” says Ravindra Puranik, oil and gas analyst at GlobalData.
In residency, Puranik identifies improved remote-operations centres and standardised seabed infrastructure as the main advances: “Open-standard docking stations built to API 17F have inductive power and data couplers that follow the Subsea Wireless Group standard. This enables vehicles from Saipem, Saab Seaeye, and Oceaneering to dock and charge at the same station. Modus demonstrated autonomous docking at an Equinor station without operator intervention.”
Communications, navigation and the limited range of tasks still present challenges, but recharging while idle makes battery life less restrictive. Typically, vehicles need between eight and 32 hours of charging, done as they sit idle between missions.
ROVs require surface control, whereas autonomous vehicles can carry out missions without continuous piloting. Resident systems stay near the asset to recharge and receive new missions without routine recovery. Puranik estimates that only three to six systems worldwide are in or have recently completed sustained commercial residency, with almost all on the Norwegian Continental Shelf (NCS). These include the Hydrone-R at Njord, the Modus/PXGEO Sabertooth contract at Johan Sverdrup and Oceaneering’s Liberty system, deployed at Åsgard, Snorre, Statfjord and Gullfaks.
Now part of PXGEO, Modus held the first resident-drone contract at Johan Sverdrup in 2023–2024 using a Saab Seaeye Sabertooth. Oceaneering’s Liberty system on the NCS has accumulated nearly 21,000 operational hours, although it is a cage-and-buoy resident ROV rather than a docked AUV. Most other systems remain in qualification. Saipem’s FlatFish completed functional acceptance tests for Petrobras in March 2026, and approval has now been granted for deployment in ultra-deep water environments in Brazil. Puranik describes the sector as “early commercial” rather than routine, which Saipem’s operational evidence supports.
At Njord, Mongini says Hydrone-R has remained operational while the site’s conventional work-class ROV was suspended on Waiting on Weather (WoW). As a result, no operational days have been lost to WoW.
Hydrone-R has also provided support for well commissioning in wave heights up to 12.5m, when conventional work-class ROV operations were not possible. Remote operations have saved more than 36,800 offshore personnel-hours, says Mongini, which would have generated hundreds of tonnes of CO₂ emissions.
Will resident AUVs dampen OSV vessel demand?
The offshore support vessels (OSV) most likely to see a demand dip as a result of AUV development are ROV support and light inspection, maintenance and repair (IMR) vessels, which run routine annual inspection campaigns on the NCS. Surface vessels hired for short attendance jobs are also likely to see a shift, as the deployment of uncrewed vessels could displace crewed ships.
GlobalData’s report cites exposed revenue streams as general visual inspection, leak surveys, light intervention and drill-support or commissioning attendance. Heavy construction, installation and repair vessels face little immediate risk, because resident drones cannot lift, lay or repair. Resident vehicles perform only limited operations, and valve operation and other manipulation are still mostly carried out by ROVs. Public data on failure recovery of AUVs is scarce, and a vessel with an ROV is still the relied-upon solution for a damaged vehicle and for tasks drones cannot do.
Vessel displacement will depend partly on whether overall subsea activity grows faster than inspection productivity improves. The effect may be more visible in vessel days per inspection than in an immediate reduction in the number of operating vessels.
Saipem expects resident robotics to progressively reduce dependence on dedicated remote survey vessels, conventional ROV support and offshore personnel. Mongini describes this as an optimisation of vessel utilisation: “Vessels are called to operate less than what is conventionally done in the industry.”
For large subsea fields where the conventional approach could call for more than one vessel, he says resident robotics could reduce the number of vessels, impacting costs, environmental consequences and risks to offshore personnel. He adds that autonomous inspection can be performed over a larger area, up to 12km from the docking station, while piloted intervention is typically within 300m to 400m, where optical communications or tether length allow continuous control.
Why autonomy will develop differently across offshore basins
The NCS offers unusually favourable conditions for resident subsea systems, including established infrastructure, remote operations and groupings of subsea assets close enough to share power, communications and support. In GlobalData’s report, Puranik suggests take-up is most likely where operators combine frequent inspection needs with costly vessel access and challenging emissions targets.
He adds: “This is providing improved flexibility in conducting offshore inspections as operators are no longer dependent on the availability of support vessels, which is particularly useful during storms and other emergencies.
“Moreover, AUVs also enhance worker safety while reducing the carbon footprint.”
Other environments will be more challenging. For example, some of Brazil’s pre-salt fields are ultra-deepwater, with infrastructure installed at depths greater than 2,000m. Less-developed offshore communications and continuing requirements for heavy intervention require large, vessel-based operations—currently, installation, pipeline repair and tie-ins rely on heavy tooling or cranes.
Saudi Arabia presents a different challenge. Its extensive shallow-water infrastructure may favour purpose-built autonomous inspection systems rather than the deepwater resident-AUV model emerging in Norway. The scale and concentration of offshore infrastructure could see the basin emerge as a potential market for autonomous inspection, particularly where systems can be adapted to local operating conditions and deployed without the need for large support vessels.
The next frontier—from inspection to intervention
GlobalData expects resident systems to become a normal part of the inspection mix on large, concentrated Norwegian fields by 2030, but notes that they may not become routine on other major offshore fields globally until at least the mid-2030s.
Eelume’s 2021 target of up to 50 robots by 2027 has not been met, and Equinor’s ambitious Snøhvit concept(a pioneering subsea-to-shore infrastructure project in the Barents Sea) has been delayed. Snøhvit Future was officially approved by the Norwegian Government in 2023, but the vision of deploying a huge, permanent fleet of AUVs there encountered major technical and economic issues.
Saipem sees the commercial model developing alongside the technology.
“Saipem sees resident robotics as an opportunity to shift value from vessel-day-based revenues toward long-term, recurring service models,” says Mongini.
He adds that this will require “combining robotic availability, remote operations, inspection and intervention services, and continuous data collection”.
Based on discussions with operators, Saipem says the most common proposition appears to be a Drone-as-a-Service model, where operators are primarily interested in inspection and intervention services and associated reports, rather than acquiring the vehicle itself. However, vehicle ownership may still be attractive in specific cases—a concept Equinor is testing.
The operational, safety and emissions benefits of AUVs ensure that automation of subsea inspection is a growing market. Looking ahead, opportunities extend beyond subsea asset management and could include decommissioning, offshore wind and carbon capture and storage.
