- Problem Definition
Water Injection pumps is used to inject the treated produced water. There are four injection pumps with engine driven. Operation team observes that preventive and corrective maintenance cost increases. This investigation aimed to analyze the major maintenance cost including spare parts and manpower. Actual cost and frequency of normal preventive maintenance (1200 hrs) due during 2014 including spare parts and manpower. Calculate failure rate occurred during 2013 for water injection pumps engines. Proposed alternative solution for the management to consider in near future.
- Development of the feasible alternatives
The Below Pareto chart summarize the failures and concerns with those four water injection pumps engines:
- Abnormal Vibration.
- High Dp across fuel filter.
- Coolant leakage.
- High Dp section strainer.
- Exhaust pipe adjustment.
- Power failure.
- Control wiring defect.
- Flow control valve.
- Discharge NRV.
Figure 1 Engines 1,2,3 and 4 Failure Categories
- Development of the Outcome for Alternative
The following alternatives were considered to assess the situation :
- Review preventive maintenance recodes and assesses the cost.
- Review corrective maintenance recodes and assesses the cost.
- Provide budgetary estimate for replacement of engine with electric motor versus the cost of preventive and corrective maintenance cost.
After studying the alternatives the following highlights been founded:
- Top overhaul maintenance carried out only for Engine 1 during March 2012.
- Major overhaul maintenance will be due on Engine 1 after 2617 hours
- Engine 2 top overhaul not preformed and unit almost due for major overhaul, only 377 hours left for major overhaul (15 days).
- Engine 3 has the lowest run hours, its ran 7811 hours so far but it has high failure rate
- Engine 4 will be due for top overhaul after 4623 hrs (192 days).
Figure 2 Run hour’s distribution on Water Injection Pumps Engines
- High number of failures occurred during 2013, which affected entire water injection system reliability and consistency.
- The highest number of failures occurred in P-1503 although this unit has the minimum run hour comparing with other three units which indicate clearly that this unit required close attention.
- Engine 1 & Engine 4 are sharing the same number of failures occurred during 2013, both units have high failure rate
- The lowest number of failures occurred in Engine 2 although the unit almost due for major overhaul maintenance.
- Selection of Criteria
Most cost and time effective alternative in order to reduce down time and increase water injection rate.
- Analysis and Comparison of Alternative
- The average number of 1200 hrs preventive maintenance carried out on each Engine per year = 7.3 service
- hrs / 24 hours = 50 days / 365 days = 3
- Each preventive maintenance cost:-
Spare parts: $ 4600/-
Manpower: $ 1100/-
Total PM cost per unit: $ 5700/-
- Total number of PM’s through the year (2014) = 7.3 X 4 = 29.2
- Total cost throughout the year (2014) = $ 166,440/-
- Selection of the Preferred Alternative
Figure 3 Cost of New Electric Motor vs. Total Maintenance Cost
- Sustainability of water injection system which lead consequently to increase daily oil production target
- Utilization of power plant capacity and power output
- Saving around $ 208,500 from preventive maintenance cost only
- Saving the cost of troubleshooting and corrective maintenance being spent on engines to rectify frequent failures
- Proper utilization of maintenance manpower
- Electric motor requires less maintenance and provide more efficiency
- No fuel gas emission “Environmental Issue”
- Performance Monitoring and the Post Evaluation of Results
Management review and approval of the proposed solution to replace the engines with electric motors will be required. However, engineering design and installation work to be carried out after budget approval
1. Preventive Maintenance register, Maintenance department, DPC ,2014.
- A Guide to the Project Management Body of Knowledge (PMBOK Guide) 5th Edition, An American National Standard, ANSI/PMI 99-001-2013, Project Management Institute, Inc, 2013
- GAO Cost Estimating and Assessment Guide, Best Practices for Developing and Managing Capital Program Costs, GAO-09-3SP, United States Government Accountabity Office, March 2009.