Whether it be pipelines or large, above‐ground chemical and petroleum storage tanks, oil and gas companies are required to constantly monitor and improve their processes, assets and equipment. Breakdowns must be kept to a minimum as they can be expensive and lead to delays or potentially dangerous situations. This is why the industry relies on the use of non-destructive testing (NDT) techniques to regularly test components and systems so that operations can run as planned.
The American Society for Nondestructive Testing defines NDT as the process of inspecting, testing, or evaluating materials, components or assemblies for discontinuities, or differences in characteristics without destroying the serviceability of the part or system. Essentially, it is when an inspection or test is completed, and the part can still be used.
For the oil and gas industry, standard practice has always been for skilled workers to use NDT techniques such as visual inspection, eddy currents testing and/or ultrasonic testing to test the required equipment. However, it is possible that advanced robotics will further revolutionise the industry in the future.
The rise of robotics in NDT
Recently, there has been growing interest in the development of robotic systems for NDT.
According to a report by market research firm, All Market Insights, global cumulative capital expenditure of inspection robots in the oil and gas industry is expected to advance to $17.83 billion from 2019-2025, representing a robust growth at 15.9 per cent per annum until 2025. In the report, inspection robots are defined as robots and intelligent devices developed and employed for inspecting, monitoring and surveying oil and gas pipelines, platforms, rigs, storage tanks and other structures.
What can robotics be used for during inspections?
As critical oil and gas assets and infrastructure are often located in remote and hazardous environments such as dusty, high temperature outbacks or in the rough waters of the ocean, hundreds of kilometres away from shore, NDT robots have been equipped with miniature sensors and actuators which can enable them to climb, crawl, swim, dive and even fly. These systems either transmit data and commands via a wire (typically called an umbilical cable or tether) or wirelessly (in the case of battery powered tetherless crawlers).
Complex structures can also be inspected by these robots as they have more degrees of freedom than humans. In an oil and gas setting, NDT robots can ensure higher productivity, higher quality, increased inspection rates and therefore, higher monetary returns compared to manual inspections.
Aside from productivity gains, intelligent robotic systems are being developed for the benefit of keeping workers out of harm’s way.
Worker safety and reaching inhospitable areas
Exposure to chemicals for long periods may cause serious harm to a worker’s health. Once a worker has been diagnosed with an occupational disease caused by chemicals, they may need to be suspended from work to prevent further harm. Apart from social costs, it has huge implications for the company as it could incur compensation payment, training for a replacement worker as well as the cost of lost productivity.
To prevent this, NDT robots can be used for mandatory inspections in inhospitable areas (such as tank interiors) to minimise the danger to human inspectors without disassembling the structure.
Furthermore, since many oil and gas assets are fully or partially-submerged in water, it presents a hazardous environment for workers.
While experienced divers will always remain an invaluable asset, autonomous underwater vehicles and remotely operated underwater vehicles equipped with NDT tools are growing in popularity as they can be deployed to traverse at greater depths (sometimes up to 1000 metres) for longer periods and in more dangerous environments.
Preventing working at heights
Inspection of tall structures such as cranes in ports need additional inspection platforms for inspectors to climb up the crane. Apart from physical discomfort, inspectors may be at risk while performing frequent inspections. With these inspections, there is the risk of altitude sickness, increased muscular fatigue, and most notably, falls. According to Safe Work Australia, falling from a height was the cause of 11 per cent of all work-related deaths in Australia between 2003 and 2015. In the U.S., falls from heights are one of the leading causes of death in the oil and gas extraction industry.
According to the Centres for Disease Control and Prevention, from 2005-2014, a total of 63 U.S. oil and gas workers died in fall events.
It is well known that the most effective way to protect workers from the risk of falling is to eliminate the need to work at height. Unmanned aerial vehicles (or drones) equipped with NDT tools and features can assist with this by allowing inspectors to remain on ground while drones carry out the inspection.
Challenges ahead
According to Global Data, the two major challenges in deploying robotics technologies in any industry are cost and reliability. Robotics are proving to be fairly reliable in enhancing operational efficiency in certain applications, such as material handling and preparation of land for drilling, especially when they are remotely managed by field operators. However, it is yet unclear if the total cost of ownership of robots and drones has a positive effect on overall operational expenditure. To overcome this concern, robotics technology providers and oilfield service providers are developing new business models, to drive the deployment of these technologies in field operations and reduce uncertainty over the total cost of ownership of robots.
Will humans still have their place?
Peter Milligan, Chief Executive Officer of the Australian Institute for Non-Destructive Testing believes human workers will remain an important asset during inspections. While Mr Milligan agrees that the acceptance of robotics in oil and gas applications is growing, he sees them as a tool and not a total solution. “Robotics has a place,” he said, “however, I firmly believe that the role of an NDT technician needs to remain in the hands of an appropriately certified person whom can make a judgement call based on skill and experience.”
Sources: Need of Robotic Systems in Non-destructive Testing Applications, Dr. Vengatesan Govindaraju and Govindaraju Palanisamy; Occupational Fatalities Resulting from Falls in the Oil and Gas Extraction Industry, United States, 2005–2014, Krystal L. Mason et al.; Inspection Robotics in Oil & Gas Industry: Global Market 2018-2025 by Robot Type, Application, System Component and Region, All Market Insights; Innovation in oil and gas asset integrity on display at AOG 2019, Australasian Oil & Gas Conference & Exhibition
