C-DRONE GUIDE · 24 AUGUST 2026

LNG Storage and Drones: Thermal Mapping of Cryogenic Tanks, Method and Price

A double-walled cryogenic tank holding its contents at around -160 °C with no insulation anomaly visible from the ground, a loading bay and its cryogenic arms inspected at a rushed pace between two truck rotations, a safety flare whose outer condition only gets checked by chance during a technical shutdown : at a liquefied natural gas storage site — a large import terminal or a small LNG/bioLNG refuelling station for heavy trucks —, classified under ICPE heading 4718, the outer envelope of the tanks and associated equipment remains a usual blind spot between two scheduled visits. The drone documents this envelope's thermal condition in a single campaign, without putting anyone in the ATEX zone or interrupting operations. Here is what it adds, what it doesn't replace, and the prices.

Published on 24 August 2026, reviewed on 24 August 2026 — regulations in force as of August 2026.

From the large import terminal to the heavy-truck LNG station: the same ICPE heading

In France, liquefied natural gas storage falls under ICPE heading n° 4718 (liquefied flammable gases of category 1 and 2, including LNG and upgraded biogas), with a regime — declaration, registration or authorisation — that depends on the capacity stored. At industrial scale, France's four onshore LNG import terminals (Loon-Plage/Dunkerque, Montoir-de-Bretagne, and two sites at Fos-sur-Mer) receive LNG by ship, store it at around -160 °C in vast cryogenic tanks and regasify it before injection into the transport network ; classified as upper-tier Seveso sites, they fall under a dedicated framework — off-site emergency plan, hazard study — on a completely different scale from a simple drone mission. At a very different scale, the growth of road LNG and bioLNG — the fuel of choice for long-haul heavy trucks, with a range of 700 to 1,500 km depending on the manufacturer — is multiplying private and public refuelling stations fitted with a modest-sized cryogenic tank, built to the ISO 16924 standard and subject, for their part, to a declaration or registration regime.

This heading imposes safety requirements, periodic checks of pressure equipment and, for Seveso sites, an enhanced surveillance plan on the operator — none of which is the drone's job. What it documents, from outside the classified perimeter, is the thermal and visual condition of the tanks' envelope and associated equipment, on the same principle as for the inspection of a hydrocarbon storage tank yard — a visual complement between two statutory checks, never a substitute for them.

Double-walled cryogenic tank: mapping cold spots without touching it

An LNG tank is almost always built as a double wall : an inner shell in contact with the cryogenic liquid, separated from an outer shell by a layer of insulation — most often expanded perlite — that limits heat ingress. This insulation is never perfect : part of the gas evaporates continuously, a phenomenon known as boil-off gas (BOG), whose rate indirectly measures the insulation's quality. When it degrades locally — perlite settling, moisture ingress, a defect at a singular point —, the tank's outer shell shows a cold spot that a thermal camera can spot, sometimes visible to the naked eye as frost or persistent condensation while the rest of the shell stays at ambient temperature.

Flying a drone over the tank shell, from outside the surrounding ATEX perimeter, systematically maps these cold spots over the tank's full height — including the dome, rarely examined from the ground — without setting foot on it or interrupting operations. A study by Pablo Venegas, Eugenio Ivorra, Mario Ortega and Idurre Sáez de Ocáriz, published in 2022 in the journal Sensors, proposes a method for automating the thermographic detection of anomalies on industrial equipment using object detection and pose estimation — an approach that transfers well to sorting the dozens of points found on a large tank (see the study on Google Scholar). The delivered report points toward a close-up check by the operator or the accredited body; it never substitutes for one.

Loading arms, flare and methane vigilance: an overflight at a safe distance

Around the tank, several pieces of equipment lend themselves to the same distant-overflight principle : the cryogenic loading arms that connect the tank to the offloading bay (tanker truck or ship depending on the site's scale), the safety flare that burns off gas in the event of overpressure, and the lagged cryogenic piping network linking this equipment. An orthophoto and a thermal pass document the visual condition of these installations — corrosion, degraded lagging, a loosened anchor point — without a technician having to work at contact range with ATEX-classified equipment.

Methane leak detection proper remains a separate exercise, covered in our guide to drone gas leak detection (LDAR) : it requires a dedicated sensor (optical gas imaging camera or onboard analyser) that a thermal-mapping drone does not necessarily carry. A study by Xu, Wang, Gu, Long, Luan, Tang, Wang and Liu, published in 2025 in the journal Drones, describes a method for quantifying diffuse methane emissions at gas sites using a drone fitted with a tunable laser sensor, with site coverage well beyond that of a ground-based measurement — an illustration of the drone's potential on this complementary strand to thermal envelope mapping (see the study on Google Scholar).

Method, flight framework and price

The mission is prepared like any classified industrial site : prevention plan, safety briefing with the HSE manager or site operations lead, precisely identifying the ATEX perimeter to overfly at a distance and the vent areas never to approach downwind, then scheduling outside offloading phases. At a large Seveso import terminal, this preparation comes with a site-specific enhanced security protocol ; at a modest-sized LNG/bioLNG station, it stays comparable to that of a standard fuel distribution site. The drone stays in the open category in the vast majority of cases, subject to a prior declaration if the site borders a populated area.

The deliverable pairs an orthophoto and a thermal map of the tank shell (cold spots, dome included) with a report focused on the loading arms, the flare and the cryogenic piping and, if the mission includes it, a campaign-to-campaign comparison to evidence any insulation drift. 2026 prices (excl. VAT) : €900 to €1,800 for a typically sized LNG/bioLNG station, rising to €2,500-4,000 for a larger import terminal or multi-tank site; an annual follow-up campaign on the same flight plan typically costs 20 to 30% less than the initial one. Our thermal imaging drone page presents the service; request a quote stating the site's scale, the number of tanks and the goal (shell only, shell and associated equipment, or a full campaign with comparative tracking).

Frequently asked questions about drone inspection of LNG storage

Can the drone measure the boil-off gas rate? No : that measurement remains the job of the tank's fixed instrumentation. The drone spots cold spots on the shell, indirect signs of localised insulation degradation, which guide the follow-up check.

Who commissions this service? The site operator — an import terminal operator, an energy company, a haulier or a distributor running an LNG/bioLNG station —, usually the maintenance or HSE manager, for a preventive audit or to evidence a drift observed in the boil-off gas rate.

Does the drone enter the ATEX perimeter? No : the mission is limited to an overflight from outside the classified perimeter, at a safe distance agreed with the operator, never coming into contact with the equipment.

Does the thermal mapping replace the statutory inspection of pressure equipment? No : it is a visual complement that prioritises the areas to examine, but the periodic check remains the job of an accredited body.

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