Navigating the gravel roads of Alaska’s oilfields in winter can be a treacherous business. Floods, ice floes and break-ups cause the topography to continually shift and bad weather often means visibility is low.
Energy firm BP has more than 200 miles of these roads criss-crossing its oilfields in Prudhoe Bay on the North Slope of the USA’s most northerly state. Up to date information on the state of these vital arteries is crucial so that trucks delivering oilfield equipment arrive both safely and on time.
The harsh environment can make monitoring the roads dangerous, expensive and time-consuming, though, so in 2006 the British firm started experimenting with using drones as a cheaper and faster alternative. After years of testing, BP became the first company to fly drones commercially in the USA after they received clearance from the Federal Aviation Administration (FAA).
Now the firm is conducting monthly surveys of the roads using a Puma AE drone manufactured by AeroVironment. The fixed-wing aircraft is approximately 1.4m long with a 2.8m wingspan and weighs roughly 6kg thanks to its ultra-lightweight Kevlar fuselage.
The radio-controlled drone is launched by hand and can either be flown manually from its two-man mobile ground control station or fly autonomously on a preprogramed route and, most importantly for operating north of the Arctic Circle, it will remain stable in winds of up to 48 kilometres per hour.
As well as high-resolution still and video cameras, the three vehicles maintained by BP are fitted with LiDAR equipment – technology that bounces laser pulses off objects to build up a 3D picture of the surroundings in a way similar to radar – which has an accuracy of 10cm, from an altitude of 45m. Data from the sensors is stored and processed at the ground station and can be produced for analysis in under an hour.
This allows the drones to create real-time 3D models of the gravel roads, pinpointing problem areas and giving engineers an indication of how much gravel is needed to fix them. The drone is also capable of carrying out volumetric analysis of the firm’s gravel pits to give them an accurate indication of how much gravel is left at any one time.
“UAVs are already helping us to cut costs, improve safety and make us more efficient,” says Curt Smith, technology director at BP’s Chief Technology Office in Houston, Texas and head of the firm’s drone programme.
“The improved technology will help BP optimise the planning of maintenance for the North Slope infrastructure in one of North America’s largest oilfields. With more than 200 miles of gravel roads used to transport oilfield equipment and rigs to location, crews maintain a 24/7 vigilance. Targeting maintenance activities on specific road areas will save time, and address safety and reliability.”
The drones, or Unmanned Aircraft Systems (UAS), are estimated to save BP up to $6m a year on maintaining the roads, but they are no one trick pony. As well as providing 3D road mapping the firm also hopes to use them to monitor wildlife, track ice floes, respond to oil spills and help in search-and-rescue missions.
“UAS promises to be a game changer for oil and gas operations,” says Smith. “The UAS also has the capability to inspect critical infrastructure, including flare stacks, tanks, bridges and power lines. It takes the Puma AE only 30 minutes to check a 1.8 mile section of pipeline; a task that would normally take a human up to seven days. In the case of facility flare stacks, it would otherwise require shutting down the facility for a person to safely inspect the flare infrastructure.”
Around Prudhoe Bay, keeping a vigilant eye on oil pipelines is particularly important. The lines are built on permafrost, which is prone to so-called frost heave – where the ground is pushed up as water in the soil freezes. This can shift the pipeline’s steel supports causing damage to the pipes that can result in leaks, so regularly monitoring of the pipelines is vital.
Unsurprisingly though, becoming the US’ first commercial drone operator was not a simple process. “BP began experimenting with UAS in 2006,” says Smith. “With high expectations and after successful test flights at NASA’s Ames Research Center, we approached the FAA for permission to fly, only to discover that there was no path for licensing. There was no rule book.”
In 2013, the FAA designated six UAS test sites operated by universities that would conduct research into how drones could be integrated into US airspace. BP and AeroVironment teamed up with the University of Alaska Fairbanks to test the concept by flying drones under a public Certificate of Waiver and Authorization (CoWA).
Many of the more recent approvals for commercial use of drones by the FAA have come under Section 333 of the 2012 FAA Modernization and Reform Act, which allows the watchdog to grant exemptions to chunks of regulations more suited to larger, manned aircraft, but as one of the trailblazers BP could take no shortcuts.
To get approval to fly commercially the Puma needed an airworthiness certificate, which meant it had to undergo a rigorous review of its design and construction process. Luckily, the Puma has also been accepted for use in the US military and this sped up the approval process. In the autumn of 2013 BP was granted a commercial CoWA and AeroVironment performed the first flight for BP in June, 2014.
BP now has a five year contract with AeroVironment to operate the three drones in Prudhoe Bay, but it’s not the only place where the company has started to use versatile flying machines. “UAS technology has other applications throughout the oil and gas industry,” says Smith.
In Singapore the firm is using drones to carry out internal inspections of oil and gas tankers nearly three stories tall and recently a drone was used to capture photos of river-deposited Cretaceous sandstones in Book Cliffs, Utah.
“The photos were used for a photogrammetry project in which a 3D model of the area was created, a task that would have been impossible without use of an aircraft given a 1,000-foot drop (300m),” says Smith. “This model will be used to train geoscientists and reservoir engineers.”
But despite their usefulness and falling costs, Smith does have some words of advice for those looking to invest in the technology. Firstly, buyers should investigate the licensing status of a drone – if the supplier doesn’t have permission to fly or doesn’t understand the process they should consider a different supplier.
Secondly, with drones, size does matter. You are far more likely to get permission to fly a small drone than a large one. They are also particularly good at getting in close and personal with infrastructure that currently requires scaffolding and climbing ropes to inspect.
And finally, despite the broad applicability of the technology, buyers must remember that their focus should primarily be on the data they want to collect and what sensors that will require. “Do not get blinded by focusing on the UAS,” says Smith. “It may be easier and cheaper to use satellite, manned aircraft or other platforms than a UAS.”