Abstract
There is a continual requirement to carry out close visual inspections of plant and equipment on offshore installations for ongoing maintenance. Accessing structures at height or live systems on a process plant poses a number of challenges. ‘Traditional’ methods-of-access to carry out inspection of high or difficult to reach parts of an installation involve using rope access techniques, scaffolding or even full-size helicopters. Rope access inspection can be time-consuming and although it has an excellent safety record it is still potentially dangerous as it involves personnel working at height which is statistically the single biggest cause of workplace fatalities accounting for 25% (5). Scaffolding as an access method for inspection can be expensive, time-consuming and also involves a significant amount of working at height or manual handling operations. While full-size helicopter inspection can mean that many parts of a rig are simply uninspectable, for example the underdeck of a platform. These inspections can also put offshore platforms at a huge commercial disadvantage as assets such as flares need to be shutoff or drilling derricks require drilling activities to stop before the inspection can be completed.
A new method of inspecting live and difficult to access assets has now been developed that allows certain inspection tasks to be performed quicker, safer and more cost effectively than traditional methods. Similar to underwater Remote Operated Vehicles (ROVs), it involves allying engineering expertise to the use of Remotely Operated Aerial Vehicles (ROAVs) for topside and above the waterline inspection. These miniature flying vehicles use HD video, HD still and thermal cameras to provide detailed images for inspection purposes. ROAVs are operated by highly trained pilots in combination with qualified engineers and plant inspectors to create authoritative technical reports and analysis. Offshore operators now have another method available to them to gather information and understand the condition of their assets without shutting down operations allowing informed decision making.
The use of ROAVs for the visual and thermal inspection of onshore structures in refineries and chemical plants has become an established technique over the last 4 years. This technique is starting to become adopted as best practice by some operators for visual inspection of certain assets such as flare stacks. The potential of the technique of using ROAV for certain inspection tasks is now being recognised in an offshore context with the first use of this technology in the North Sea in January 2012.
This paper provides an introduction to the concept of inspection using ROAVs, overview of the technology, benefits of the technique, limitations of its application, safety considerations, case studies and a look to the future for the industry.
