By Danny Constantinis (Chairman & CEO) EM&I Group, Malta.
EM&I lead a number of Joint Industry Projects (JIPs) including one concerned with safety in confined spaces. This has been a problem for many years and a number of fatalities and injuries have occurred.
Robotic alternatives are now available, so it is not necessary to put personnel at risk working in hazardous areas, at height, or in confined spaces. The legal, financial, and reputational risks of fatalities in confined spaces can cause serious problems for companies if they have not considered alternative safer methods, such as robots or remote methods of inspection, maintenance, and cleaning, etc.
Professor Andrew Woods of the BP Institute at Cambridge University recently carried out a study of fatalities in confined spaces, which revealed that many senior managements are unaware of the safety levels required by regulators – usually 1 in a 1,000,000 or ALARP (As Low As Reasonably Practicable).
His research has revealed that most companies are operating below the broadly accepted levels of safety…
His research has revealed that most companies are operating below the broadly accepted levels of safety with consequent concerns on reputation, costs, and legal challenges if senior managers knowingly allow work to be carried out when safer methods are available at reasonable cost.
In 2020, HM Treasury in the United Kingdom assessed that the cost of an incident resulting in a fatality might be in the order of GBP 2 million (~US$2.75M). The ALARP (As Low As Reasonably Practicable) principle, and regulatory guidance suggests that expenditure to mitigate the risk should be in ‘gross disproportion’ to the cost of an incident, maybe up to ten times the cost.
“We let robots do all the dangerous work” commented Danny Constantinis (Chairman & CEO) of the EM&I Group. “There are robotic and remote methods of inspection and repair available now which are safer, faster, more economic, and greener than traditional methods as there are less people involved.”
As far as floating production assets are concerned, nearshore or jetty moored assets are much easier to inspect than offshore where different rules apply. With the current rush to install Floating Storage Regasification Units (FSRUs) around European coasts many will probably end up in offshore or deepwater moorings.
The classification societies will almost certainly apply similar rules to those applying to FPSOs, Drillships and Semisubmersibles. Even in nearshore and/or jetty moored assets, which are usually in river estuaries and near large conurbations means that diving operations are difficult and dangerous in strong currents and virtually nil visibility.
Also, as far as LNG and hydrogen is concerned cryogenic storage presents additional challenges in the ‘warming up’ and ‘cooling down’ of assets to minimise out of service periods. Robotic methods of inspection can be carried out at temperatures much lower than manned entry methods so tanks can be back in service sooner.
FSRUs usually have very large tanks so manned methods of inspection are difficult…
FSRUs usually have very large tanks so manned methods of inspection are difficult when it comes to coping with high level inspections which would normally require scaffolding on very delicate tank linings. Most of the ‘sloshing’ damage of the liquid LNG or hydrogen occurs at mid-high level in the tanks so this is important.
Remote methods use tripods and telescopic masts with cameras lowered through tank openings to achieve the same objective and are much safer and faster. Out of service periods can be very costly so the quicker tanks can be back in service the better.
EM&I has been in the asset integrity management business for over 35 years and has worked on hundreds of offshore assets during this period so are very experienced in Inspection Repair and Maintenance (IRM) and lead a number of JIPs including HITS (Hull Inspection Techniques & Strategy) on behalf of the Global FPSO Research Forum, together with ‘FloGas’ and ‘FloWind’ for floating gas and winds assets.
This keeps us in touch with all of the main stakeholders…
This keeps us in touch with all the main stakeholders in each market sector so that all of the innovations are ‘industry driven’ and what owners and operators want. This has worked well in the FPSO industry where the HITS JIP has been operating successfully for 8 years.
The ODIN® diverless UWILD (Under Water Inspection in Lieu of Drydocking) was one of the first innovations to come out of the HITS JIP, quickly followed by the NoMan® remote camera and synchronous laser scanning technologies. These have already been used with great success on many offshore projects, so are well proven.
The ODIN technology allows us to examine the hull, propellor, rudder, bilge keels, sea chest inlets, and mooring chains, etc., using integrity class ROVs, and also to examine critical valves in operation from within the hull while the asset is on hire, on station, and in use, so eliminating any out of service periods.
The valves can be inspected using patented ODIN access ports installed adjacent to the valves, so that specialised cameras on manipulators can be inserted through the access ports to examine the valves in operation.
If any anomalies are detected remote methods of isolation can be used to allow repair or replacement of faulty valves.
REMOTE TANK CLEANING
It has become increasingly clear that, whilst remote tank inspection techniques are now developing apace, all of the present and known-of future techniques employ line-of-sight, that is to say that they need a clear line of sight to the structure under survey. The success of such remote inspection techniques therefore is heavily dependent upon the extent to which such lines-of-sight are achievable. RBI is now a Class-accepted methodology for carrying out Class surveys on floating units.
To date the predominant inspection strategy…
To date the predominant inspection strategy has been the continuous hull survey cycle permitted by the Class Societies’ Rules whereby the prescriptive Class inspection requirements are applied i.e., general visual inspection (GVI) of entire tank, close visual inspection (CVI) of a defined portion of the tank and ultrasonic thickness measurements (UTM) of defined structure within the tank. Up until very recently, remote inspection techniques were unable to demonstrably carry out UTM to an acceptable Class standard. They have also been limited in performing GVI and CVI by the level of cleanliness in the tank. Of note however is that this is not from a failing in their functionality (unless their line-of-sight requirement is considered to be their failing and not one attributable to lack of cleaning).
Instead, this is due to a lack of appreciation during the evaluation phase of the RBI strategy development. Because of these issues, Remote Inspection Techniques (RIT)s have not demonstrated effectively their ability to satisfy the inspection requirements of the continuous hull survey strategy under which they are being deployed. As a result, the benefits of remote inspection, which include significant safety benefits, have yet to be fully appreciated by operators and Class alike; in effect we have been trying to fit the square peg of modern RIT methods into the round hole of traditional prescriptive inspections. With the increased uptake of RBI for hull structure, there is an opportunity for remote inspection to be shown to be commercially beneficial and much safer.
…what is the objective of adopting an RBI strategy…
We return therefore to the original question of what is the objective of adopting an RBI strategy and realise that the answer is not Class compliance but survey compliance where the potential outcomes from the survey have been risk assessed as part of the process and either mitigated or deemed acceptable. It is clear therefore that the adoption of any remote inspection technique really needs to be driven by the inspection strategy