Less than a decade ago, the flying of drones for commercial purposes was heavily restricted. However, in 2016, the Federal Aviation Administration (FAA) introduced the remote pilot certificate as well as rules and regulations for the piloting of small unmanned aircraft (drones). According to the FAA, as of December 2019, there are now over 160,000 certified remote pilots and more than 420,000 commercially registered drones in the United States.
In a report by BusinessWire, the Global Oil & Gas Drones Market is projected to reach USD 4 billion by 2020. Drones have rapidly garnered interest in this industry due to the overall benefits they offer during pipeline inspections.
What are the Benefits of Using Drones for Pipeline Inspections?
Pipeline inspections in the oil and gas industry must be done frequently. Leaks and other defects can result in millions of dollars in losses and can also pose a threat to human and environmental health. Currently, inspections of vast pipeline networks typically involve flying personnel over the areas under consideration using airplanes or helicopters. However, this inspection method is both expensive and dangerous.
Drone inspections, on the other hand, are considerably less expensive than conventional fly-over inspection techniques. Additionally, since drones are unmanned, i.e., the pilot can be positioned in a remote location, these inspections are inherently safer than manual methods. This is especially beneficial when conducting investigations in hard-to-reach or hazardous areas.
Drones are also renowned for their exceptional lead times. Qualified drone crews can be deployed for inspection jobs rapidly, while it typically takes a longer time for manned aircraft crews to mobilize.
Furthermore, drones can also be equipped with numerous accessories to provide them with various inspection functionalities. For example, specialized cameras and sensors can be added to the drone to allow them to detect several signs of defects, such as dying vegetation, oil leaks, and methane leaks. These unmanned devices are also equipped with GPS technology, allowing maintenance crews and contractors to locate the defective areas with high precision.
How Are Drones Used in Conducting Pipeline Inspections?
Thermographic imaging
Thermographic imaging is a type of infrared imaging technique. This technology makes it possible for drones to detect the heat radiated from objects with or without visible illumination. Aerial thermographic inspections are, therefore, ideal for inspecting piping networks that transport fluids with temperatures that are different from the ambient temperature (e.g., oil and gas product pipelines).
Thermal cameras and sensors identify defects in insulated pipelines by scanning the thermal radiation around the pipe. Where insulation flaws exist, anomalies in the form of heat loss will be detected by the drone’s thermal imaging systems. Early identification of thinned or damaged insulation can help minimize economic losses as well as prevent potentially life-threatening accidents.
Thermographic imaging can also be used to identify defects in buried pipeline systems without performing costly excavations. Leaks in underground pipes affect the temperature of the surrounding soil. For example, if a pipeline transporting hot fluids is damaged, the resulting leaks will heat the ground around it. This temperature difference can then be spotted by thermal cameras mounted on drones.
Methane leak detection
Methane leaks are a severe threat in natural gas pipeline systems. Not only can they result in economic loses, but this gas is also extremely flammable and can ignite easily from the slightest spark. The subsequent explosion can be catastrophic, resulting in significant infrastructure damage, and in some cases, loss of life. As such, manual pipeline inspections in the vicinity of methane leaks are considered highly dangerous.
Unmanned drones equipped with methane sensing technology allows pipeline inspectors to identify, locate, and quantify methane leaks from a safe, remote location. Laser spectroscopy equipment mounted on aerial drones analyzes air samples to detect the presence of methane around product pipelines.
This technology works by emitting laser pulses at a specific spectral range and analyzing the characteristics of its reflection. If methane gas is present, the light from the laser is partially absorbed; thus altering the properties of the reflected beam. Operators can then use the data collected by the drone to calculate the concentration of methane present.
Vegetation index
Not all pipelines in the oil and gas industry transport hydrocarbon-based fluids. Saltwater, also known as produced water, is a common byproduct of oil extraction. This water is typically pumped through wells along with the extracted oil product. Produced water has a high level of salinity. Leaks, therefore, can usually spell disaster for nearby crops and farmlands. Saltwater can destroy acres of farmland and can result in costly clean-up costs.
Vegetation Indices (VI) are values used to quantify vegetation cover, vigor, and growth dynamics in a specific area. Drones equipped with multispectral cameras are used to measure the surface reflectance of objects (plant life in this case) to highlight the properties of the surrounding vegetation.
By using drones and multispectral imagery to assess vegetation data, drone operators and analysts can highlight areas with possible saltwater leakage, which may otherwise be undetected by manual visual inspections.
Construction
In addition to inspecting existing pipelines, drones are also useful in identifying risks associated with new pipeline construction. Whether pipeline networks are installed by open-trench or trenchless methods, new construction projects can be plagued by budget shortfalls, schedule overruns, and unforeseen costs.
During the pre-construction phase, drones can be used to inspect or survey the proposed construction site to gather data, such as topographic information, site geometry, and nearby existing infrastructure. They can also be used to detect potential health and safety hazards, which may complicate the construction process.
When construction begins, drones can identify potential dangers for construction personnel; thus, supporting the construction process and preventing accidents and injuries. Another useful application of drones during construction is the real-time monitoring of activity. Precise orthophotographs of the site can support project managers with tracking daily changes and construction progress.
What We've Learned
Drones are quickly becoming a valuable tool for inspecting pipelines in the oil and gas industry. The remote operation drones permit inspections in hazardous and hard-to-reach pipelines and facilities with little to no human health and safety risks.
However, what makes drones truly unique is their ability to be outfitted with various cameras and sensor technology. This allows multiple types of defects and leaks to be detected based on numerous properties and characteristics.