Aboveground storage tanks (ASTs) are critical infrastructure in industries such as energy, water, and chemicals. These tanks require regular inspection to ensure structural integrity, operational safety, and compliance with evolving regulatory standards. Traditionally, inspections have involved scaffolding, rope access, and even tank entry-methods that come with significant safety risks, high costs, and operational downtime. The integration of drone technology is rapidly changing that landscape, offering a safer, more efficient, and data-rich alternative.
Advantages of Drone-Based Inspections
-
Improved Safety: Drones eliminate the need for inspectors to climb tanks or enter confined spaces, reducing accident risks and minimizing exposure to hazardous environments.
-
Enhanced Data Quality: Modern drones are equipped with high-resolution optical, thermal, LiDAR, and ultrasonic sensors, enabling detailed imaging and defect detection on hard-to-reach surfaces.
-
Operational Efficiency: Inspections can be completed in a fraction of the time required for manual methods, often without taking tanks out of service.
-
Cost Savings: Companies avoid expenses related to scaffolding, extensive labor, and operational downtime. In some cases, drone inspections have saved over $1 million by deferring full internal inspections.
-
Repeatability and Consistency: Automated flight paths ensure consistent data collection, supporting accurate trend analysis and proactive maintenance planning.
How the Process Works
Drone inspections typically begin with pre-inspection planning, where the team maps out flight paths, identifies potential hazards, and defines the scope of work. Depending on the need, drones can be deployed externally or internally. For internal inspections, confined-space drones can enter through access hatches and navigate in partially filled tanks without requiring full drainage.
Once deployed, the drone captures high-resolution images, videos, and sensor data. Techniques such as photogrammetry and orthomosaic mapping stitch together hundreds of overlapping images to create distortion-free, geographically accurate site maps. These models allow precise measurement of tank dimensions, assessment of secondary containment volumes, and monitoring of changes over time. After the flight, the data is analyzed and compiled into comprehensive reports that include defect identification, repair recommendations, and documentation suitable for regulatory compliance.
Applications and Impact
Drone inspections are effective for both external and internal tank assessments. Externally, drones can quickly survey roofs, walls, and foundations for signs of corrosion or damage-without the need for scaffolding or rope access. Internally, drones equipped for confined spaces can inspect walls, floors, and ceilings even when some residual product remains, allowing operators to delay more invasive inspections without compromising safety.
The versatility of drones allows them to access tanks in remote or challenging environments, and their advanced sensors expand their usefulness. For instance, thermal imaging can detect leaks or insulation failures, while ultrasonic payloads assess wall thickness and identify hidden corrosion. The data collected supports compliance with industry standards such as API 653 and STI/SPFA SP001, and helps facilities maintain up-to-date Spill Prevention, Control, and Countermeasure (SPCC) plans.
In one notable example, a drone inspection of a tank bottom-conducted while the tank was still in operation-was completed in six days. The data collected allowed the facility to defer a full internal inspection for up to 15 years, leading to substantial savings and uninterrupted operations.
Looking ahead, continued advancements in sensor technology, automation, and data analytics will further empower operators to predict maintenance needs, extend asset life, and ensure regulatory compliance with greater confidence. Integrating drone inspections represents a strategic investment in innovation that delivers measurable benefits now and unlocks new possibilities for asset integrity management in the years to come.
For more information about drone implementation contact Scott Nowicki, Technical Director of Inspections, at scottn@ttienv.com To request a proposal or schedule an inspection contact Carol LaRosa, Inspection Business Administration, at caroll@ttienv.com
NOW HIRING – Petroleum Equipment Installer (La Plata, MD)