Advances in sensing capabilities have enabled oil and gas operators to incorporate autonomous drone technology into increasingly sophisticated tasks, including maintenance inspections of infrastructure and thermal imaging to spot methane or other gas leaks.
The use of unmanned aerial systems (UAS), particularly in combination with artificial intelligence, provides the ability for advanced inspection strategies such as predictive maintenance and asset management, and its deployment is likely to grow in the industry as digitalisation continues.
This will be accelerated by declining hardware costs and further advances in sensing and remote operations technologies, while a wide variety of drone solutions have already been adopted within the industry.
An integral aspect of oil and gas operations is regular and comprehensive maintenance and inspections, especially on offshore platforms, but the high-risk nature of working offshore necessitates the development of increasingly safer inspection methods.
Drones have enabled operators to perform maintenance remotely, greatly improving safety and substantially reducing the time needed for inspections.
Oil and gas facilities can have hundreds of different assets, kilometres of piping, and thousands of connection points where leaks or other infrastructure failures can occur.
This includes substation and power distributions systems, which are traditionally expensive, hazardous and time consuming to inspect.
However, power distribution inspections are considered critical maintenance that when left unchecked can lead to serious incidents and ongoing downtime events.
Automated oil and gas drone inspection systems can reduce the time needed to conduct power distribution inspections by between 50 to 80 per cent, allowing them to be conducted more frequently.
Traditional inspections typically can cost up to $250,000, depending on the size of the facility, but automated drone systems lower costs dramatically, as well as decreasing the incidence of power distribution failures.
Drones can also be used for floating roof inspections, which are conducted to assess whether heavy rain or storm conditions have sunk the roof systems on above-ground tanks.
Oil tank inspection workers are required to inspect the tanks and drains frequently, which pose height risks to the workers, and can thus be neglected and not inspected as regularly as they should be.
Drones can reduce these times by up to 90 per cent and provide real-time results to enable smarter and data-driven business decisions, as well as allowing rapid response to potential failure situations.
Another use example that mitigates height-based hazards are drone flare stack inspections, which do not require shutting down the operation and are capable of acquiring high-resolution data and thermal images even when the flare is live.
When defects are detected in the flare stack, drones can perform more frequent inspections and monitoring to evaluate the defect’s rate of propagation and the flare stack’s fitness for service.
A key advantage of using drones to perform offshore rig maintenance is their ability to do so as a non-destructive testing (NDT) method.
NDT is the use of non-invasive analysis techniques to quantitatively inspect, measure, and evaluate the safety and integrity of mission-critical infrastructure and systems without interfering with the overall operation or future usefulness of those assets.
Research has found that using UAS-based inspection activities can achieve between a 25 to 75 per cent time and cost saving compared to conventional inspection methods.
The cost figures used by the research excludes the cost of preparation, transportation, and accommodation, which can be substantial for certain maintenance activities.
For example, scaffolding a structural leg can require about 336 hours of setting up time and the associated cost for the scaffolding alone is estimated to be about US$130,000.
The transportation and accommodation cost for field workers and other materials is also high.
Another innovative application of drones to oil and gas operations is in conjunction with optical gas imaging (OGI) technology, which is used to ascertain whether an area contains toxic gas build-up and limit exposure to gas that would normally set off a wearable gas monitor.
Similarly, workers gauging large tanks can judge the emission characteristics of the tank before placing themselves in any potential gas cloud.
OGI gives workers actionable and precise information about the toxicity in their immediate surroundings without endangering them to detect such hazards.
One of the complications posed by OGI is the volume of footage and associated data produced by thermal cameras, creating a need for more sophisticated software and expanded processing capacity.
A possible solution was investigated by the Southwest Research Institute (SwRI) and the US Department of Energy’s National Energy Technology Laboratory, involving the use of smart leak detection technology which can remotely expose methane leaks in real-time with the aid of a drone.
Maria Araujo, Research Development Manager at SwRI, said the technology for stationary applications had been developed, but autonomous performance from drones would make life easier for operators and reduce the volume of streamed data.
She noted the ability to monitor large areas was an efficacy point for conventional drone inspection, but it now was a moving platform that could potentially quantify a methane leak by acquiring more than just a strict 2D image.