An offshore oil and gas production platform is one environment where an equipment failure could have a huge negative impact on employee safety and lost production. Yet, offshore platforms are one of the most difficult locations in the world to operate and maintain equipment.
In most cases, supplies and skilled labor can only reach these platforms via helicopter or ship, so bringing replacement equipment, technical specialists, spare parts, and tools to the platform is very expensive.
Oil analysis alerts the maintenance team to problems that may damage a vital system, playing a crucial role on almost every offshore platform. An effective oil analysis program plans maintenance based on equipment condition rather than time intervals, providing efficient allocation of scarce resources.
Most offshore platforms take oil samples and deliver them by helicopter to onshore labs for analysis. After obtaining the results, they are sent back to the platform.
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The disadvantage of this method is that it could take a week for the sample to reach the lab, another week for the lab to carry out the analysis, another week to process the results and get them back to platform, and maybe one more week before technicians view the results and take action.
By the time the results are acted upon, the equipment may have failed. This could put the employees at risk and cause production outages or require expensive shipments of replacement parts.
A new approach involves sending a technician with a portable oil analysis tool to the rig. The technician samples all the equipment on the rig and provides immediate feedback. Equipment failure can be avoided by taking immediate maintenance actions. The operator can also determine the assets that do not require any maintenance or the equipment that requires non-urgent maintenance. This information enables valuable on-platform resources to be used for other activities.
Value of Oil Analysis on Offshore Platforms
The total expense of operating a typical production platform over its 10 to 20-year life cycle is more than $1 billion, so operating costs per day can be estimated at $100,000 to $300,000. There are millions of dollars worth of machinery on a typical offshore platform that is critical to the crew’s safety and whose failure can easily put the platform out of operation.
For a long time, oil analysis has been the gold standard in the offshore industry for monitoring the condition of critical equipment. Oil analysis determines amount of various metals in the oil, providing a quick and cost-effective method of gauging the amount of wear in the machinery.
In addition, oil analysis measures viscosity and solids formed by oxidation to determine the oil condition. By monitoring oil condition, the risk of catastrophic failure and the high cost of changing and disposing of oil in heavy machinery can be reduced.
Like many other activities, oil analysis is much harder to perform offshore than onshore. Generally, the crew operating the platform do not have the equipment or time required to perform oil analysis themselves. They collect samples from the various rotating equipment on the platform, such as turbo gas powered generators, flooded screw compressors, fire water pumps, gearboxes, diesel engines, crane engines, pumps, hydraulic systems, etc.
The samples are then labeled, loaded onto a helicopter, and sent to onshore labs, while the crew waits for the results. If any of the samples are mislabeled, the results may be inaccurate. If a positive result is received, immediate action must be taken by technicians before validating the results as it would take too long to analyze another sample from the same piece of equipment.
Moving from Onshore to Offshore Oil Analysis
A major oil producer, who is now employing this method, sent an oil sample to a lab and received the results almost a month after, indicating a problem with an air compressor. Unfortunately, the company had to incur the cost of replacing the machine as the compressor failed a day before the arrival of the results.
The producer asked John H. Carter Inc. to bring a portable oil analyzer to its platform and provide immediate oil analysis results. After researching the available portable oil analysis instruments, John H. Carter Inc. chose the Spectro Q5800 portable analyzer. The Q5800 comprises of the following four modules:
- Kinematic viscometer determines viscosity without solvent and with a low sample volume
- Infrared spectrometer with flip top cell design tests for water content, Total Acid Number/Total Base Number, new fluid validation, and soot
- Elemental analysis module conducts wear metal and sand/dirt analysis to detect abnormal wear and contamination ingress with X-ray Fluorescence (XRF) technology
- Filtration Particle Quantifier (FPQ) to facilitate solvent-free particle counting to less than 4 µm/ml
The oil producer then signed a contract with John H. Carter Inc. to provide on-site oil analysis at its offshore platforms in the Gulf of Mexico. A Carter technician takes a helicopter to travels to offshore oil platforms with a portable instrument, and conducts the same tests provided by full-service laboratories.
The portable instrument, which fits into a backpack and is easily transported on a small helicopter, provides the same accuracy as full-size laboratory instruments. Immediate results are also provided by the all-in-one unit. If there is an abnormal result, the platform crew can immediately act to resolve the problem.
The ability to immediately re-check every positive result to ensure the accuracy of the initial test results is another advantage of the portable analyzer. Re-testing prevents false positives and enables significant cost savings by avoiding unnecessary replacements or repairs.
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The Spectro Q5800 portable analyzer
Examples Where Offshore Oil Analysis Saved Time and Money
John H. Carter Inc. has been providing on-site oil analysis to an oil producer for a year. There have already been several cases where the savings from on-site analysis exceeded the full year's cost of service.
1. For instance, technicians on one platform replaced the diesel engine on a crane. The technician who visited the platform and tested the oil found that the viscosity was 70 when it should have been 120. Additional tests showed the presence of diesel fuel in the oil. When a mechanic put dye in the fuel supply, it was found that diesel fuel was leaking into the oil sump through a broken injector line. This leak could possibly damage the engine or even cause a fire. Thanks to the oil analysis, the problem was fixed with a low cost solution – replacement of the injector line.
2. In another example, the oil analysis results on a large gas turbine compressor indicated a high metal particle count. The technician queried the platform’s maintenance team and found that a valve in the lube oil system had been replaced recently. The technician wondered if the spike in the oil particle count might have occurred in response to this maintenance, so he flushed the lube system and ran another test. The results indicated a much lower particle count, though still above normal values. Following a discussion with the maintenance foreman, the decision was made to do nothing immediately but to retest the equipment the following month. The particle count had returned to normal levels when the equipment was retested. The maintenance foreman said that if the oil had been tested by an onshore lab, there would have been no means of conducting an immediate follow-up study. At the minimum, it would have been essential to perform vibration testing and possibly perform even more expensive repairs.
Data Management and Reporting
The results of offshore oil analysis are uploaded to the Spectro Scientific SpectroTrack information management system. The results can be viewed by the maintenance team on the platform, as well as by onshore managers and analysts who track trends and provide recommendations on whether or not to invest in a certain piece of equipment.
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Carter technician inserts sample into instrument.
Conclusion
The current oil analysis method used on most offshore platforms takes up to a month to send samples to a laboratory and obtain results. By allowing testing on the rig and delivering immediate answers to the maintenance team, on-site oil analysis has the potential to offer major value and benefits.
Faster results can help to avoid unnecessary maintenance and prevent breakdowns. The savings are realized by the potential to get immediate answers and better manage equipment uptime on the offshore rig.
This information has been sourced, reviewed and adapted from materials provided by AMETEK Spectro Scientific.
For more information on this source, please visit AMETEK Spectro Scientific.