Tessella – software for asset condition monitoring
Feature Articles, May  04  2010 (Digital Energy Journal)

- R&D IT consultancy Tessella has developed a software solution to enable oil and gas companies set up and deliver their own asset condition monitoring – and to optimise the use of this equipment by operators.

R&D IT consultancy Tessella, HQ Oxford, UK, has a software solution which oil and gas companies can use to set up and deliver their own asset condition monitoring.

Condition monitoring is a big challenge for many companies – it is one thing to add lots of sensors and gather a mass of data, but quite another thing to turn it into answers to key questions such as, “do I need to change this part now or can it wait another 3 months?”

The Tessella approach allows the operating company to lay down benchmark measurements that model a well functioning system. Automated comparison of recent data with the reference benchmark will spot any drift away from normal operation. Tracking that drift enables early warning of potential issues. The advantage of this approach is that the operating company can install the solution at their premises and monitor hardware provided by third parties giving them a trusted view on condition of the whole plant whether it is owned by them or not.

The solution can be used for a wide range of different equipment. “It puts together the experience we’ve developed studying a range of different components,” says Nick Clarke, technical manager at Tessella. “Our work in the transport sector has clearly demonstrated that this is very much a viable approach.”

“Every piece of equipment has a unique set of operating signatures, so configuring a system in advance to recognise all expected failure signatures requires a lot of time and specialist knowledge. By allowing them to measure real signatures and identify problems though signature change, our framework hands control back to the operator. It also means the monitoring remains effective when the reality of ‘normal’ component behaviour doesn’t match the theoretical levels from the design specifications.

“The idea is enabling clients to get more uptime out of the plant and predict problems before they happen,” says Mark Claxton, energy global account director with Tessella. “So companies can be prepared for everything, do repairs in scheduled shut downs, rather than have to react to failures or schedule maintenance interventions at short notice.”

Through regular automated assessment, the software can spot gradual onset failure, such as slow leaks or a stretching chain. The alert thresholds are defined in the software by the operator either as a hard limit or as a % change from the benchmark. In addition to using the total amount of change as an alert trigger, the software can also use how fast something is changing, or how variable that change is, to predict in advance when component degradation will cross a threshold.

Tessella offers services to configure the solution at the client’s location and provide remote administration and support for the installed software. The solution allows the client to configure for themselves how to set the benchmark measurements, how to measure and interpret change, how to define tolerances and how strict they should be, and what alerts to raise when tolerances are exceeded. The configured alerts include guidance to operators on how to respond. This allows each client to match the solution to their exact needs and to fit tolerances to their the risk profile and intervention strategy.

“You really want a system that tells you where you are sitting in your acceptable range – and what the recent movement has been within that range – so you get an early indication of a change in behaviour,” says Dr Clarke. “Equally, you have to recognise that all systems fluctuate and the monitoring needs to target persistent change to avoid false alarms. We’ve put a lot of thought into that.”

Some customers use this approach in parallel with the equipment supplier. Although condition monitoring services may have been provided by the supplier as part of their guarantee, the operating company uses the Tessella solution to independently measure equipment performance during this initial phase. This gives them a dataset of system behaviour from day one which will prove invaluable when identifying potential faults in later years, after the guarantee has expired.

Ultimately, Tessella hopes to reach a point where all maintenance processes are carried out as a result of intelligence from a condition monitoring system – rather than being done after a fixed period, as most maintenance is done today.

One of the most important features of a solution like this is capturing the operating company tacit knowledge.

“Operators often already have an intimate knowledge of their equipment – what failures they can expect after which periods of time, and what is an acceptable decay – and Tessella can help configure the solution to work with this know how,” says Mr Claxton.

People

Tessella is also developing tools which can determine how consistently and efficiently the equipment is being operated by different staff members.

A machine is most efficient when transitioned smoothly between its various operating levels and set in the correct level for the job in hand. Continuous starting, stopping or shifting modes is almost certainly inefficient. The operating style can have a “huge impact on energy costs and the strain on the asset,” says Dr Clarke.

Tessella has implemented similar systems in the rail industry, which monitor how trains are being driven. “Up until now, it hasn’t been possible to know how different drivers operate, without having an assessor in the cab with them,” Dr Clarke says, “and this will always make a driver take more care than usual. By measuring how operators truly perform, day in day out, the least efficient staff can be given extra training and mentoring to allow them to reach the levels achieved by the best.” Dr Clarke finished by observing “the most effective organisations concentrate their maintenance and repair efforts at their highest risk assets. People also need attention in order to maximise their performance, and our software uses the same ideas to allow companies to target their training resources.”

<<BACK