CASE STUDY

Detecting a Bearing Fault on a Top Drive Motor — and Keeping the Rig Drilling Until Planned Maintenance

On an active drilling rig, an unplanned top drive failure doesn’t just stop production — it triggers contract penalties. When a bearing fault appeared on the top drive motor of a National Oilwell Varco TDS11 SA at 2:40 AM, Predicore didn’t just detect it — it managed the risk. With 40 days to the planned maintenance window, a controlled monitoring plan kept the rig drilling safely until the fault could be fixed on schedule. The result: 50 production hours protected, zero unplanned stoppage, and $128,500 saved.

The Client & Asset

Client: Leading oil & gas operator.

Monitored asset: A National Oilwell Varco TDS11 SA top drive installed on an active drilling rig — a mission-critical piece of equipment operating at height, under variable load, where an unplanned failure halts drilling operations and triggers contract penalties.

The Problem: Advanced Bearing Damage on the DS Motor

On February 19, 2023 at 2:40 AM, Predicore AI™ detected an anomaly in the DS motor of the top drive and immediately notified the on-duty supervisors with specific inspection recommendations. Vibration levels at the affected bearing were 45% above normal values compared to equivalent top drives operating under the same conditions.

Three days later, a no-load test was performed at 100 RPM. The Monitoring Center analyst confirmed a bearing fault in the DS motor based on elevated impact vibrations and high-frequency noise in the acceleration spectrum — consistent with advanced bearing damage.

Left undetected, the fault would have progressed to catastrophic motor failure mid-operation, forcing an emergency shutdown, emergency part logistics, and a contract breach with the operator.

The Solution: A Controlled Monitoring Plan to the DTM Window

Following Predicore’s recommendations, the team carried out re-greasing and mechanical adjustments, reducing motor vibration by 10%. With 40 days remaining until the scheduled Drill-to-Maintenance (DTM) window, Predicore guided a controlled monitoring plan: biweekly no-load tests, continuous tracking of bearing fault frequencies, and a backup motor prepared as contingency.

The asset reached the DTM window without failure — the fault was fixed on schedule, not in an emergency.

Stats

Proven at scale. Trusted by operations that can’t afford to stop.

  • USD $128,500

    Total estimated savings

  • USD $32,500

    Repair & transport avoided

  • $96,000 — 50 production hours secured

    Drilling continuity

  • Reached planned DTM — zero unplanned stoppage

    Outcome

Frequently Asked Questions

How is a bearing fault detected on a top drive motor? Continuous vibration monitoring compares a motor’s readings against equivalent top drives under the same conditions. Elevated impact vibrations and high-frequency noise in the acceleration spectrum point to bearing damage, often long before catastrophic failure.

Can a rig keep drilling after a bearing fault is found? Yes — with the right monitoring. In this case a controlled plan of biweekly no-load tests, fault-frequency tracking, and a backup motor kept the rig drilling safely for 40 days until its planned maintenance window.

What does an unplanned top drive failure cost? Beyond the repair itself, an unplanned failure forces an emergency shutdown, emergency part logistics, and can trigger contract penalties with the operator — costs that far exceed a planned intervention.

About Predicore

Predicore is a Maintenance Operations Intelligence platform that combines proprietary wireless sensors, purpose-built AI, and a 24/7 certified analyst team to detect equipment faults before they become failures — connecting asset risk with the people responsible for acting on it.