One of the most obvious and established uses for unmanned aerial vehicles and unmanned underwater vehicles (UAVs and UUVs, respectively) in an offshore context is to carry out inspections on facilities – oil and gas platforms, wind turbines and the like.
UAVs can inspect high areas such as cranes, “crawler” robots can enter tanks and traverse hull structures, while UUVs can inspect pipelines and underwater structures among other tasks.
Proponents argue this is not only more efficient in terms of costs and time, but also safer than humans carrying out the same work. Aerial drones can access areas that would require humans to use ropes and harnesses, crawlers can enter spaces that would be inaccessible or extremely dangerous for humans, while UUVs can carry out work that previously required the use of trained divers.
BP provided a test case for this argument in March this year, when it successfully used an aerial drone and a crawler to inspect a riser pipe on its Thunder Horse platform in the Gulf of Mexico.
“What used to take a ropes team several weeks to complete, was done by the drone and the crawler in a matter of hours,” the company said in a press release.
No electromagnetics were used in the crawler’s inspection, meaning that even in the event of a loss of power the crawler would have remained fixed to the platform. The crawler, known as “Maggie”, was equipped with strong rare-earth magnets and a high-definition camera, as well as a wireless gas detector with an alert range of up to 300 m.
The drone used for the work can fly to within 5-8 m of its target and used a stabilised high-resolution camera to zoom in on areas of interest. It also carried an optical gas imaging camera that can ‘see’ potential gas clouds.
But for all their potential, drones still have limitations.
Workships Contractors general manager Philip Woodcock noted problems faced by UAVs in the offshore wind sector in sister publication Offshore Wind Journal.
Many of the concerns he raised are equally applicable to the offshore oil and gas sector, especially with the development of unmanned platforms and the increasing use of “walk-to-work” vessels.
For example, operators, who may “spend hours staring at a small screen” piloting a drone aboard smaller craft such as crew transfer vessels, are at risk of motion sickness, which can lead to poor inspection quality and the risk of striking the structure under inspection, potentially causing damage to the drone, the structure, or both.
There is also the matter of recovery – many UAVs ‘land’ by being caught in the operator’s hands, which brings its own challenges in an offshore context.
Mr. Woodock said “when the vessel is pitching and rolling in a seaway, this method of recovery will reduce flying time because any incident offshore that results in a loss of control will also cause the drone and data to be lost into the sea, with little chance of recovery. So the operator will err on the side of caution and not fly in marginal conditions.”
Size and weight also play a role. Mr. Woodcock noted that additional capabilities require additional equipment, affecting the amount the drone must lift and therefore reducing flying time. Smaller drones are also limited to wind speeds of eight miles per second, so can be grounded by bad weather.
Still, many businesses are making innovative use of the technology.
Fishing for collaboration
The commercial arm of the Scottish Fishermen’s Federation, which already offers vessels for services such as guarding subsea infrastructure, debris clearance and survey tasks, recently launched a service with UK-based Texo Drone Survey and Inspection (Texo DSI) offering fishing vessel-launched UAV services to the UK offshore oil and gas sector.
Texo DSI’s drones are capable of mounting technologies such as light detection and ranging, ultrasonic thickness testing, optical gas and hyperspectral imaging, and remote/supply drop capabilities. The company also provides close visual, thermographic and internal UAV inspection services, and aims to further expand its range with microwave sensors, alternating current field measurement and phased array capabilities.
In Norway, efforts are underway to look at how UAVs and drones can be used to transport cargo between offshore vessels and offshore installations as an alternative to conventional vessel-based crane operations, as reported in sister title Marine Electronics & Communications.
The partners in the “Safer Logistics from Unmanned Logistics Helicopter” research project are four Norwegian technology companies: Griff Aviation is a heavy-cargo drone developer and manufacturer; STABLE focuses on advanced stabilisation technology; Olympic Subsea operates a fleet of 11 offshore construction vessels; and project leader Norut develops and operates autonomous control systems for unmanned airplanes, including in challenging weather conditions in northern waters.
Another such venture involves a Netherlands-based collaboration between Robotica in Maintenance Strategies (RiMS) and the Dutch Drone Company. Together, they are seeking to provide “a full drone package service” of inspections for ship hulls, mobile offshore structures and cranes for the maritime and offshore industries.
At present a human operates the controls of most drones. However, 2018 promises to be a big year for autonomous drones and larger vessels in the offshore sector.
Hrönn, described as a “light-duty offshore utility vessel” by developers Kongsberg Maritime, Automated Ships and Bourbon, is scheduled to enter service later in 2018.
Initially operating in remotely piloted, “Man-in-the-Loop Control” mode, Hrönn will use algorithms developed during this stage to transition to fully automated and autonomous operations.
The vessel has several uses relevant to the offshore service sector, including pipelay and cable touchdown monitoring, carrying out surveys and deployment, recovery and monitoring of ROVs and UUVs. It will also be capable of providing firefighting support, working in cooperation with manned vessels.
In April, Norwegian companies Kongsberg and Wilhelmsen announced a joint venture named Massterly that aims to be the world’s first full-service autonomous shipping company.
While the joint venture will initially be focused on shortsea and inland waterways, Massterly managing director Tom Eystø sees potential for autonomous vessels in the offshore sector, for example by “implementing technologies that are driven by autonomy onto manned ships” for very standardised jobs, which could reduce stress on crew.
Meanwhile an autonomous ground robot will soon carry out inspections at an operation oil and gas installation for the first time, as part of a project run by Total E&P, robotics firm Taurob, Technische Universitaet Darmstadt (TU Darmstadt) and the Oil and Gas Technology centre.
As part of an 18-month trial, the robot will first operate at Total’s onshore Shetland Gas Plant before moving offshore to the Alwyn platform. It can perform visual inspections, read dials, level gauges and valve positions, measure temperature and gas concentration and navigate narrow pathways and up and down staircases, all the while detecting and navigating around obstacles and humans it encounters.
With such extraordinary abilities becoming commonplace, it seems reasonable to ask, for how much longer will there be humans on site to navigate around?