Dear Editor,
ExxonMobil is in the news again, this time they published a photograph of what appears to be the two ends of a screw compressor casing. In addition, they stated “A detailed assessment of the compressor has found an axial vibration of the compressor rotor was the initiating event of the technical issue experienced on January 27. The resulting vibration within the compressor was the cause of the mechanical seal failure initially reported.”
From this brief comment, and the fact that the compressor parts had to be sent to the manufacturer to diagnose the cause of the failure, one could deduce that ExxonMobil is practicing breakdown maintenance.
It would be expected that a world class organisation such as ExxonMobil would have been using a Reliability Centred Maintenance (RCM) programme for such a complex piece of machinery as the FPSO.
According to the Society of Automotive Engineers (SAE) JA1011 Standard, seven questions need to be answered satisfactorily and in the following sequence to determine if an organization is following RCM standards:
1. What are the functions and associated desired standards of performance of the asset in its present operating context (functions)?
2. In what ways can it fail to fulfil its functions (functional failures)?
3. What causes each functional failure (failure modes)?
4. What happens when each failure occurs (failure effects)?
5. In what way does each failure matter (failure consequences)?
6. What should be done to predict or prevent each failure (proactive tasks and task intervals)?
7. What should be done if a suitable proactive task cannot be found (default actions)?
If ExxonMobil had an RCM programme, their answer to question 6 would have been, implement a vibration and used oil analysis programme to predict a potential failure of this critical piece of equipment. A high-quality portable Fluke vibration tester costs around US$10,000.00 and ExxonMobil currently has an inhouse Oil Analysis Programme called Mobil Serv Lubricant Analysis Service. With these two programmes, ExxonMobil could have detected the increased axial vibration and would have observed increased levels of wear metals in the used oil early enough to have prevented a failure of the equipment. I say this with confidence because when I worked with ExxonMobil L&PS as the Senior Sales Engineer in the Caribbean, I was responsible for providing Technical Support and training for large Industrial and Commercial customers and would have detected this potential failure using the oil analysis programme which was then called Signum.
I would not be surprised if ExxonMobil were to claim that they have an RCM programme in place on the FPSO. In fact, they could use the RCM question 5 to justify their Run to Failure programme. I would expect that they decided that the failure of the gas injection compressor did not matter because they could flare the gas with impunity and the operation of the FPSO would not be affected. They could still operate at full capacity without any loss of profits and with no consequences for the failure.
ExxonMobil’s mediocre maintenance programme should be of grave concern to the Guyanese people, especially given the fact that a Risk Assessment would find that there is a high probability of an oil spill occurring at some time. In addition, the local organisation (EPA) responsible for monitoring ExxonMobil’s maintenance programme obviously does not have the expertise and capability to do so. Given my expertise in maintenance, I should be pleased to provide direction and technical advice to the EPA, pro bono publico.
Yours truly
Tara Singh
