Drones deployed for offshore operators provide FPSO maintenance

Unlike conventional tanker inspections conducted in drydock, FPSO cargo oil tank inspections occur offshore, adding layers of complexity. Harsh offshore environment challenges include:

●       Surface contamination: Over time, FPSO tanks accumulate layers of wax, dust and sand, making accurate UTM readings difficult.

●       Measurement inconsistencies: Air gaps or bubbles between the UT probe and the corroded steel surfaces can cause errors.

●       Structural complexity: FPSO cargo oil tanks contain intricate internal structures, and early drone-based UT probes had fixed angles, making it difficult to achieve perfect alignment with target surfaces.

●       Limited flight time: Traditional battery-powered drones had limited endurance, reducing overall inspection efficiency.

Recognizing these challenges, Terra Drone developed and integrated several technologies into the Terra UT drone system, specifically designed for offshore inspection capabilities, and the technology has been accepted by ABS, DNV and Bureau Veritas. 

These advancements were carried out through a joint R&D program with MODEC, ensuring solutions tailored for offshore environments. These advancements include an enhanced cleaning module equipped with a redesigned high-power brush and motor, enabling the drone to remove thick wax and debris before performing UTM measurements. This feature ensures clearer readings and reduces the need for manual intervention.

The technology also offers in-flight angle adjustment for the UT probe, allowing it to adjust mid-flight, ensuring precise alignment with the inspection surface. This eliminates the need for frequent landings to manually correct the probe’s angles, significantly improving efficiency and conserving battery life.

In addition, tethered drone technology results in the power supply tether extending flight time, overcoming the limitations of traditional battery-powered drones. This also ensures comprehensive tank inspections can be completed in a single deployment, reducing operational down time.

Real-world impacts

By collaborating with worldwide partners like Terra Drone Indonesia and Terra Drone Brazil, the drone technology has been successfully deployed on FPSOs across the globe for inspections. 

Drone-based UTM campaigns have cut tank inspection durations by up to 50%, minimizing FPSO downtime and improving productivity. By eliminating the need for rope access teams in confined spaces, the risk of accidents and personnel exposure has been significantly reduced. Moreover, lower manpower requirements and faster inspections translated to substantial cost reductions for FPSO operators.

Future developments

Terra Drone is actively continuing research and development. The company is aiming to create an explosion-proof ground control station to enable non-manned entry operations for enhanced safety; automate drone flight and measurement processes to improve accuracy and efficiency by reducing human intervention; and implement alternative thickness measurement technologies to complete and enhance existing UTM methods.

The adoption of drone technology for FPSO maintenance demonstrates that robotics and automation can significantly enhance the safety, efficiency and reliability of offshore inspections. As the offshore energy industry evolves, further advancements in drone-based technologies will ensure that FPSO operators can maintain asset integrity with minimal risk and maximum efficiency.

Terra Drone also has released an indoor inspection drone, Terra Xross 1, which enables stable flight at one-third of the cost of conventional models. The company envisions integrating a UT inspection module to it and expanding its user base to those who have not adopted drone inspection technologies.