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Table of Contents
Case Study
Reduced Downtime by 4 Days with an Optimized Scope of Spares and Manpower
Table of Contents
Background
Industry
Oil & Gas
Solution
Engine Condition
Monitoring System
(ECMS)
Make & Model
Caterpillar 3516B Engine
Asset
Offshore Jack-up Rig
Objective
To optimize the scope of a scheduled Caterpillar 3516B Top End Overhaul by using pre-overhaul diagnostics, thereby reducing costs, downtime, and resource utilization without compromising engine reliability.
Challenge / Problem Context
The Caterpillar 3516B engine was due for its 2nd Top End Overhaul as per OEM recommendations based on running hours.
The rig owner had a budget constraint, making a full OEM-recommended overhaul difficult to justify.
The customer wanted to minimize downtime to ensure that drilling operations were not delayed.
What Did We Do?
Neptunus, being the preferred maintenance partner across multiple rigs for this customer, advised conducting pre-overhaul diagnostics using torsional vibration analysis to determine the true health of the engine.
Our team carried out a detailed engine health inspection using the Engine Condition Monitoring System, evaluating parameters such as combustion quality, vibration signatures, and component condition.
The diagnostic report highlighted fuel injection quality issues and signs of wear on the crankshaft main bearings, while other key health parameters (liners, cylinder bores, etc.) were found within acceptable OEM limits.
Based on this data, Neptunus recommended performing only a Top End Overhaul instead of proceeding with the full 2nd Top End Overhaul as per OEM guidelines.
During dismantling, the diagnostic findings were reaffirmed, as liner hatch marks and cylinder bore dimensions were well within OEM tolerances.
Results That We Achieved
Direct cost savings of ~$52,000 by avoiding unnecessary overhaul scope, significantly increasing rig profitability.
Time savings of 4 days (8 days instead of 12), enabling the rig to resume operations faster and supporting the overall repair schedule.
The engine has been running smoothly for over 6,000 hours since the optimized overhaul, validating the accuracy of Neptunus’ diagnostics.
The customer’s technical team and rig crew could focus on drilling operations without concerns over engine reliability.
