Interocean offers UAV-based ultrasonic thickness measurement inspections.

 

By Alex Clark

The offshore energy sector requires safer, more efficient and sustainable inspection methods. Operators need to manage aging infrastructure, comply with stricter regulations, and aim to reduce carbon emissions while maintaining the integrity of offshore assets.

One of the most pressing concerns in offshore operations is the risk posed to personnel during structural inspections. According to the International Association of Oil & Gas Producers, over 60 percent of offshore safety incidents involve working at height or in confined spaces: environments that are inherently hazardous. Traditional inspection methods, such as rope access and scaffolding, further expose workers to risk, extend downtime, and increase operational costs.

Simultaneously, industry regulations are becoming stricter. Classification societies require regular ultrasonic thickness measurements (UTM) to monitor the structural integrity of key offshore assets. Traditionally, these inspections necessitate significant preparation, specialist personnel and considerable logistical effort to achieve compliance.

For over 18 years, Interocean Marine Services has been delivering safe, professional and high-quality services to the offshore energy sector. Focused on marine assurance, inspection, and operational support, Interocean collaborates with drilling contractors, asset owners, and classification societies to improve safety, efficiency, and sustainability in offshore drilling operations.

Interocean is implementing class-approved UTM inspections using unmanned aerial vehicles (UAVs), aiming to reduce risk, improve efficiency and establish new safety standards.

Advantages of Remote Inspections

Ensuring the structural integrity of offshore assets is crucial for safety and operations. Inspections are needed for preload tanks, ballast tanks, voids, chain lockers, and other enclosed areas to detect corrosion, material loss, and weaknesses.

Traditionally, these inspections require personnel to enter confined spaces, often using rope access or scaffolding. These processes increase safety risks, extend downtime and inflate costs.

Interocean has reduced human entry into high-risk areas by using UAV-based UTM inspections. It is among the first companies approved by ABS and DNV for class-certified drone inspections. This method has cut the need for scaffolding and rope access by up to 80 percent, while maintaining accuracy and compliance. This technology advances offshore safety and efficiency, making inspections more reliable and data-driven with minimal risk to personnel.

Integrating UAV-based UTM inspections into offshore operations offers several benefits. It reduces exposure to hazards by employing UAVs to handle measurements in confined spaces, reducing the need for personnel entry. There is up to 80 percent reduction in scaffolding and rope access, so UAVs lessen reliance on high-risk, labor-intensive methods. Faster and more efficient inspections are enabled by UAVs that gather data quickly and accurately, minimizing downtime. There is also a lower carbon footprint: Fewer offshore personnel means less helicopter transport and accommodation costs, cutting emissions.

 

A drone can move readily in confined spaces, reducing risk and improving inspection efficiency.

 

Proving the Technology

The practical application of UAV-based UTM technology has been demonstrated aboard the Valaris Viking jack-up rig, where the system conducted thickness measurements inside preload tanks. The trial, observed by both ABS and DNV, validated UAV-based inspections, confirming that: class-approved UTM inspections can be conducted using UAVs; high-accuracy thickness measurements can be obtained without direct human access; and personnel exposure to hazardous environments can be reduced.

Following this validation, Interocean received official approval from ABS and DNV to perform class-certified UAV-based UTM inspections, facilitating the broader adoption of this technology across the offshore sector.

Data-Driven Inspections

The quality and accuracy of inspection data are important in maintaining the safety and integrity of offshore and industrial assets. Traditional methods often depend on isolated snapshots of asset conditions, which may overlook emerging structural issues or fail to provide comprehensive data sets that include both quantitative and qualitative insights.

UAV-based UTM inspections offer a more advanced, data-rich approach. UAVs capture detailed, repeatable thickness measurements that enhance long-term asset monitoring. Real-time 3D modeling provides operators with detailed defect maps and digital models, facilitating more effective planning. With predictive maintenance, asset owners can optimize for actual conditions instead of scheduled inspections, reducing downtime and costs. This data-driven methodology ensures that early warning signs of structural deterioration are detected before they become critical, helping to prevent accidents and unplanned operational failures.

With ABS and DNV approval, Interocean has effectively used UAV-based UTM inspections in various offshore settings. Applications include preload and ballast tank surveys (reducing confined-space entry and ensuring compliance with standards, which decreases offshore personnel days) and hull and structural assessments (obtaining precise thickness data in limited spaces without needing rope or scaffolding).

By using UAV technology, offshore operators are lowering risks, enhancing data accuracy and simplifying maintenance, striving for a safer, more sustainable industry.

 

Interocean NDT (nondestructive testing) Inspector and UAV Pilot Alex Wilson demonstrates a UAV-based UTM drone at a training facility in Aberdeen.

 

Case Studies

Interocean has demonstrated its capability to help major operators meet safety and legislation requirements and improve personnel safety through UAV-based inspection technologies. The company’s recent inspection on board the Macro Offshore Crossway Eagle self-elevating accommodation jack-up unit illustrates how drone technology can enhance safety while ensuring compliance with DNV rules and regulations.

The primary objective was to conduct a visual inspection of two spud cans to evaluate their condition and adherence to DNV class guidelines. Additionally, Interocean inspected a ballast tank and a void space within one of the pedestal cranes for structural anomalies and defects.

The inspection team included a Civil Aviation Authority-approved UAV pilot and a certified inspection technician, whose expertise ensured the safe and efficient execution of the inspection process. The Elios 2 drone was deployed through a deck-access hatch, enabling remote inspection via its live video feed. The UAV conducted a comprehensive visual assessment of critical structural elements, including internal walls, chord-to-can connections, and supporting braces and stiffeners. The drone systematically navigated through the tanks and spud cans, capturing high-resolution visual data to ensure thorough coverage of all areas. Each flight was recorded, allowing inspectors to perform detailed post-flight analysis and closely examine any potential concerns. The collected data were compiled into detailed photographic and technical reports, providing a clear and accurate assessment of the structures’ condition.

UAV technology yielded several advantages. By using drones, personnel did not need to enter confined and potentially hazardous environments, reducing exposure to safety risks. Inspection findings were available instantly, enabling real-time discussions and immediate client feedback. The inspection adhered strictly to class rules, ensuring regulatory compliance without compromising safety. The entire workscope, including travel, was completed swiftly, achieving an estimated 30 percent cost and time reduction compared to conventional methods. Coatings and steelwork conditions were thoroughly assessed and verified by a qualified coatings and inspection technician.

By integrating UAV-based inspections, Interocean aims to enhance safety standards while maintaining high levels of precision and regulatory compliance. The successful execution of the Macro Offshore Crossway Eagle inspection underscores the impact of drone technology in high-risk environments, setting a new standard for safety and efficiency in the industry.

A Step Forward

By incorporating UAV-based UTM inspections, Interocean is aiding the offshore industry in adopting more data-driven maintenance strategies. As offshore energy infrastructure ages, reducing risk and maintaining asset integrity will be crucial for long-term sustainability.

Future advancements in digital twin technology, AI-driven defect analysis, and autonomous UAV systems could further enhance efficiency and decision making, diminishing the need for human entry.

With a focus on safety, efficiency, and innovation, Interocean is contributing to changes in how offshore inspections are performed, ensuring that both personnel and assets are protected.

Interocean’s Chief Commercial Officer Alex Clark has extensive expertise in high-risk operations and leadership within the maritime and energy sectors.