For many years, oil analysis has been a crucial tool for routine maintenance and cost prevention on oil rigs. Equipment failures on these rigs pose significant safety risks and can lead to missed production targets, which are quickly felt.
The remote locations of offshore rigs add to the challenge, making routine maintenance particularly costly. Typically, skilled personnel and necessary supplies must be transported by ship or helicopter, resulting in high expenses for bringing technical specialists, replacement equipment, spare parts, and tools to the platform.
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Given these challenges, oil analysis is vital for alerting maintenance teams to potential issues that could harm critical systems. A well-implemented oil analysis program helps optimize resource allocation by focusing maintenance efforts on actual equipment conditions rather than fixed time intervals.
Currently, most offshore platforms collect oil samples and transport them by helicopter to onshore laboratories for analysis. After the results are obtained, they are then sent back to the platform, creating a time lag in addressing potential issues.
Typical Production Platform Costs
Operating a typical production platform over its 10 to 20-year life cycle costs over $1 billion, translating to daily operating expenses of $100,000 to $300,000. These platforms house millions of dollars worth of machinery crucial for crew safety, and equipment failure can swiftly bring operations to a halt.
Oil analysis plays a key role in measuring metal content in the oil, offering a cost-effective and rapid method to assess machinery wear. Additionally, it evaluates oil conditions by detecting oxidation byproducts and measuring viscosity. Regular monitoring of oil conditions helps mitigate the risk of catastrophic failures and reduces the significant costs associated with oil changes and disposal in heavy machinery.
Typical Equipment Sampled by Oil Analysis Flooded Screw Compressors
- Flooded screw compressors
- Turbo gas-powered generators
- Fire water pumps
- Diesel engines
- Gearboxes
- Pumps
- Crane engines
- Hydraulic systems
Challenges
The problem with this strategy is that it may take a week for the sample to arrive at the lab, another week for the lab to conduct the analysis, another week to process the results and return them to the platform, and possibly another week before technicians view the data and take action.
By the time the results are processed, the equipment may have failed. Along with this delay, oil reports from onshore contract oil labs may lack the thorough diagnostics required to advise rig staff and make proactive decisions.
The frustration of receiving a recommendation to resample, which might arrive four weeks after the initial sample, can lead to skepticism about the effectiveness of oil analysis as a maintenance tool.
Image Credit: AMETEK Spectro Scientific
Value of Oil Analysis on Offshore Platforms
Recently, an offshore rig in the Gulf of Mexico contacted a Louisiana-based dependability services provider to discuss ways to improve its oil analysis program. The slow turnaround time from its onshore lab aggravated the flaws of the current approach.
Key problems to address:
Frequent Resamples Due to Mislabeling: Collected samples from the various rotating equipment on the platform were misidentified, leading to erroneous results by the contract lab. Policy demands action on CAUTION or ALERT status samples, so long delays caused operators to discard results.
Missed Compressor Failure: A genuine problem detected by oil analysis on a failing air compressor was received one month after the compressor had failed without warning. The rig operator then incurred extra costs replacing it. It can cost $250 K for expedited freight and installation charges alone to replace a critical system ASAP.
Resources for Onsite Oil Analysis: The rig operator had submitted their operating budget for 24 months to the oilfield license holder. They were not in a position to dedicate rig personnel to operating onsite oil analysis equipment in addition to sampling.
Proposed Solution
The oil producer requested that the reliability service provider bring a portable oil analyzer capable of delivering comprehensive analysis, immediate results, and a full report with recommendations within the same shift.
The service provider proposed sending a Level III Vibration Analyst/Tribologist Service Engineer who possessed the required safety certifications and was familiar with rotating equipment and maintenance strategies onboard the rig.
The primary challenge was to select a portable, solvent-free oil testing device capable of measuring abnormal metals, viscosity, oil chemistry, and particles and providing detailed reports. The chosen solution was the FieldLab system.
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It is composed of four modules:
- An infrared spectrometer featuring a flip-top cell design, which evaluates parameters such as Total Acid Number/Total Base Number, water content, soot, oxidation, and validates new fluids.
- A kinematic viscometer that measures viscosity without the need for solvents and requires only a small sample volume.
- A Filtration Particle Quantifier (FPQ) that counts particles greater than 4 μm per milliliter without using solvents.
- An elemental analysis module that utilizes X-ray Fluorescence (XRF) technology to analyze wear metals and sand/dirt, detecting abnormal wear and contamination.
In this scenario, a technician goes by helicopter to offshore oil platforms with a portable instrument and conducts the same tests as full-service laboratories. The portable equipment is as accurate as full-size laboratory instruments, yet it fits into a backpack and can be flown on a small helicopter.
The all-in-one unit delivers fast oil analysis findings. If there is an abnormal outcome, the platform personnel can take prompt action to remedy the issue.
Another significant advantage of the portable analyzer is the ability to immediately re-check any positive results to guarantee that the initial test results are correct. Retesting reduces false positives and allows for significant cost savings by avoiding unneeded repairs or replacements.
Initial Examples
Several situations have previously been reported in which the savings from on-site oil analysis outweighed the service's annual cost.
- Technicians on one platform rebuilt a crane's diesel engine. When the technician arrived on the platform and tested the oil, it had a viscosity of 70 cSt rather than the expected 120. The technician conducted more testing and discovered the presence of diesel fuel in the oil. A mechanic put dye in the fuel supply and discovered that a broken injector line was leaking diesel fuel into the oil sump. This leak had the potential to damage the engine or start a fire. The oil analysis results made it possible to repair the problem with a low-cost solution: replace the injector line.
- In a different scenario, an oil analysis on a large gas turbine compressor revealed an unusually high metal particle count. Upon investigating, the technician learned from the platform’s maintenance team that a valve in the lubrication oil system had recently been replaced. Suspecting that this maintenance might have caused the particle count to increase, the technician flushed the lube system and conducted another test. The results showed a significantly reduced particle count, though it remained above typical levels. After consulting with the maintenance foreman, the team decided to hold off on immediate action and retest the equipment the following month. When retested, the particle count had returned to normal. According to the maintenance foreman, if the oil had been tested by an onshore lab, there would have been no chance to do an immediate follow-up study. This might have led to additional steps, such as vibration testing or even costly repairs.
Data Management and Reporting
The results of offshore oil analysis can be sent to the TruVu 360 fluid intelligence system. The results are available not only to the platform's maintenance crew but also to onshore managers and analysts who monitor trends and make recommendations on whether or not to invest in specific pieces of equipment.
Summary
Currently, the oil analysis process on most offshore platforms involves sending samples to a lab and waiting for results for up to a month. On-site oil analysis could significantly enhance this process by enabling tests to be conducted directly on the rig and providing immediate feedback to the maintenance team.
This quicker turnaround can help prevent equipment failures and reduce unnecessary maintenance. The main advantages of on-site analysis are the rapid acquisition of results and improved management of equipment uptime, leading to cost savings and more efficient operations on the offshore rig.
Image Credit: AMETEK Spectro Scientific
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.