Release date: 13 November 2014
Keeping road grader vehicles or drill rigs on course in a harsh Alaskan winter can be a slow, difficult business. So, too, can inspecting a flare stack on a refinery cooling tower. But, the growing use of unmanned aerial vehicles (UAVs) is helping organisations such as BP to change the way in which these necessary tasks are managed.
BP has been testing UAVs for its own purposes since 2006, although widespread commercial use was previously limited by cost, regulation and privacy issues. That all changed earlier this year, though, when the Federal Aviation Administration (FAA) approved BP and California-based manufacturer AeroVironment’s request to fly the Puma AE UAV at BP’s Prudhoe Bay oilfield on Alaska’s North Slope. It’s the first time the FAA has authorised the commercial operation of a UAV over land in the US. Not all UAVs are the same. The Puma, for example, is a radio-controlled, fixed-wing vehicle around 1.8 metres (six feet) long with a two-metre (seven-foot) wingspan.
Made of ultra-light Kevlar, it weighs less than seven kilograms (15 pounds). Other fixed-wing UAVs are ‘autonomous’, which means their route, speed and height are all pre-programmed ahead of flight. Both versions can fly for around three-and-a-half hours and remain stable in winds of up to 50 kilometres (30 miles) an hour. This makes them ideal for checking pipelines and mapping land outcrops for exploration purposes.
There are also radio-controlled multi-rotor UAVs – effectively mini-helicopters – that are smaller and have a shorter range. These are perfect for checking vertical structures, such as flare stacks and cooling towers, as well as flat roofs and electrical lines. BP is also investigating their potential use inside vessels and tanks. The beauty of a multi-rotor - This link opens in a new window UAV is that it can collect accurate data from a structure at a distance of seven to nine metres (25-30 feet), without having to shut it down.
Time it takes a Puma AE to check a three-kilometre section of pipeline. This would take a human up to 7 days
Length of pipeline at BP’s Prudhoe Bay field in Alaska
Number of pulses of light per second that LiDAR equipment transmits in order to collect 3D images
UAVs are controlled by mobile ground stations crewed by one person flying the machine and someone else operating the onboard cameras, usually accompanied by subject experts onsite to analyse the pictures and data as they come in.
The machinery is highly sophisticated technology, which is one reason why UAVs are classified as aircraft. But, the real innovation is in the kit they carry. As well as high-resolution photography and video cameras, the fixed-wing versions carry the latest light detection and ranging (LiDAR) equipment, which incorporates remote sensors that use laser pulses to collect 3D images.
The laser scanner transmits up to 400,000 pulses of light per second, recording the time delay between transmission and reception to calculate elevation values. Those values are then integrated with information from the UAV’s global positioning system (GPS) and orientation measurements to produce a ‘point cloud’ – a set of data points – showing the location of crops, forests, roads, railways, airports, bare earth, mountains, valleys, lakes, rivers, glaciers, buildings and other urban developments.
Since LiDAR - This link opens in a new window can be reflected from any object the laser pulse strikes, up to five returns are collected per pulse. The multiple returns are recorded and each point is assigned a classification to identify landscape features. The intensity of the reflected energy is also captured and analysed: all of which makes it very useful for high-resolution topographical mapping and 3D surface modelling.
For BP in Alaska, this technology is proving invaluable at its Prudhoe Bay site, where floods, ice break-ups and ice floes constantly alter the topography, making other monitoring methods difficult, costly and time-consuming. Using UAVs and LiDAR technology, the team is able to create highly accurate, real-time models that help to keep drivers on course along gravel roads, even in low-visibility conditions. The UAVs also help to scan BP’s pipeline network to identify areas that need repair from frost damage.
Elsewhere, UAVs are helping BP’s exploration team to produce cost-effective 3D models of onshore outcrops in Azerbaijan. At its site in Hull, UK, the unmanned Cyberhawk ‘octocopter’ has helped to assess the integrity of a 100-metre (330-foot) cooling tower, removing the need for scaffolding and people working at height.
The regulatory environment for using UAVs differs from country to country, determining how and where this technology can be used. But, with costs falling and increasingly sophisticated technology – of both the machines themselves and the sensors and cameras they carry – the future looks very promising for UAV use across BP.