Lubricant is considered as a life blood for rotating machineries. The mineral or synthetic base oil and precise additive package are used to formulate a specific lubricant for prescribed application. The base oil comprises of 70-99% in the lubricant forms the foundation of the lubricant, and most of the characteristic in lubricant comes out from base oil. The rest in lubricant is comprised of additives, which is a mixture of different complex chemicals used to add on/enhance/suppress performance of lubricant required for application. The typical lubricant composition is shown in Figure I.
Figure I: Lubricant Composition
The lubricant forms oil film under operating condition and provides lubrication by separating contacting surfaces. In addition to lubrication, other important functions of lubricants are cooling, cleaning, protecting contacting surfaces, sealing, power transmission, etc. The functions of a typical lubricant are shown in Figure II.
Figure II: Functions of Lube Oil
Lubricant Condition Monitoring (LCM)
Proper lubrication plays a critical role in improving equipment reliability as improper lubrication is one of the major causes of equipment failure. Therefore, it is important to monitor the condition of in-service lube oil to ensure the protection of critical rotating equipment. Saudi Aramco has SAP-based Lubricant Condition Monitoring (LCM) System, which monitors thousands of critical rotating machines containing millions of gallons of lubricants spread across all operating facilities. The LCM system issues Work Order to collect lube oil sample for all registered equipment as per schedules specified under available maintenance plan. The collected samples are sent to dedicated laboratories for performing number of critical tests like viscosity, acid number, base number, additive metals, wear metals, contaminants, etc., to assess the condition of in-service lube oil. The test results are reviewed in LCM by lubrication engineer and recommendation are provided as necessary for implementation, which ensures the reliable operation of critical equipment monitored through LCM. The process flow of LCM is shown in Figure III.
Figure III: LCM Functioning
There is a clear need to evaluate the lubrication performance in each operating facility and understand the followed lubrication practices, which help identify gaps and implement lubrication best practices to achieve lubrication excellence. To understand the current lubrication performances, it is utmost important to benchmark the lubrication performances of each Saudi Aramco operating facilities using LCM System.
Benchmarking is the practice of establishing goals and targets for process performance levels and identifying required improvement areas based on the best practice or industry-specific preferred practice. In simple terms, benchmarking is a continuous improvement tool that in the case of lubrication, allows specific operating facility to rate their performances/practices against those of the front-runners in the company.
Therefore, it is imperative to develop achievable KPIs for all operating facilities to monitor the improvements of lubrication performance for each participating operating facility.
Five (5) measurable lubrication KPIs have been developed to monitor the lubrication performance of participating operating facilities. The established 5 KPIs are given below:
The oil samples are classified into “Compliant Sample” and “Noncompliant Sample” based on sample analysis result. A “Compliant Sample” means all analyzed parameters of the sample are within the acceptable limit incorporated in LCM System based on different International Standards and OEM recommendations. A “Noncompliant Sample” means one or multiple analyzed parameters of the oil sample are outside the acceptable limit.
Noncompliant Samples are then classified based on their causes of noncompliance (Failure Modes). There are mainly four failure mode categories: Contamination, Oil Mixing, Dissolved Gases and Normal Degradation. The Lubrication KPIs are shown in Figure IV.
Figure IV: Lubrication KPIs
Annual Corporate Lubrication Benchmarking Report is being issued since 2015 for all operating facilities from five Admin Areas. The significant improvement of lubrication performance have been noticed across the company as a result of adopting the best practices specific to lubrication challenges captured in the benchmarking report. The Sample Compliance rate KPI has been improved to 94% in 2020 from 82% in 2015. The corporate lubrication performance trends are given below:
The LCM system potentially saves millions of dollars from participating operating facilities by avoiding premature oil replacement, preventing bearing replacement and avoiding chemical cleaning through early detection of noncompliant samples and implementing the recommended corrective action to mitigate the issues.
Benchmarking of Saudi Aramco against Peer Companies
In an effort to improve and share best practices in the field of lubricants, Saudi Aramco approached 12 Oil & Gas and petrochemical companies to compare and benchmark the lubrication program of Saudi Aramco with peer companies. The survey covered four elements; oil sampling and lab analysis, off-line monitoring of oil condition and quality, benchmarking reporting at corporate level and online monitoring of oil condition and quality. Seven oil companies have participated in the survey. It was revealed that Saudi Aramco is among the best performer in the machinery lubrication performance monitoring and reporting process. The response of peer companies against Saudi Aramco are captured in figure V.
Figure V: Lubrication Performance of SA and Peers Companies