When shale shakers cease to operate as expected, a variety of items need to be checked and the problem eliminated. This section presents a general guideline for troubleshooting some common problems observed in shaker operations. Refer to the manufacturer’s service manual for specific or special instructions for each design.
Always contact the manufacturer’s service department when you have a situation where damage or injury could result, and especially where electrical shock hazards may exist.
| Shaker Problem: | Items to check: | Solution: |
|---|---|---|
| Motor will not start/run | Power supply incompatible | Check power and wire motors |
| Power supply disconnected | Reconnect power | |
| Power cable failure | Replace or repair cable | |
| Motor damage | Replace or repair motor | |
| Overloaded or overheated motor | Replace overload protection with proper type and rating |
|
| Over-greasing motors | Remove drain plug before greasing; motor must be rebuilt if damaged |
|
| Drive belt too tight | Adjust according to manufacturer's recommendations |
|
| Motor overheating | Moisture in motor | Open electrical covers and allow to dry; reseal covers properly |
| Undersized overload heaters | Replace with properly sized heaters | |
| Single phasing | Check that all leads are well connected and voltages are consistent at each leg |
|
| Unbalanced terminal voltage | Check for faulty leads, connections, and transformers | |
| Bearing failure | Replace motor | |
| Drive belt problems | Check manufacturer's recommendations and adjust or replace |
|
| Noisy operation | Worn bearings | Replace motor |
| Shock mount/float mount problems | Check for obstructions, over/under inflation, or breakage; adjust or replace |
|
| Loose or cracked motor mounts | Re-torque and/or replace motor | |
| Shipping brackets not removed | Remove the brackets | |
| Damaged or cracked shale shaker basket | Repair or replace after checking with manufacturer |
|
| Object leaning against or bumping shaker basket | Remove object or reposition to prevent damage |
|
| Cuttings moving erratically on shaker screen | Unit not level | Adjust installation to level position; check tank for level alignment |
| Motor rotational problem | Check manufacturer's recommendations |
|
| Shock mount damage | Replace mounts | |
| Drive belt too tight | Adjust to proper manufacturer's setting | |
| Motor failure | Replace motor | |
| Mud overflowing shale shaker screen | Screens plugged | Replace or clean screens |
| Wrong screens | Adjust screen size up or down to determine proper selection |
|
| Incorrect deck angle | Temporarily adjust screen angle up or down |
|
| Water-wet screens in an oil-based drilling fluid | Change screens; add more oil-wetter to drilling fluid | |
| Oversized cuttings returned to active system | Torn shaker screens | Replace or repair torn or worn shaker screens |
| Worn tensioning device | Replace | |
| Leaking bypass valve | Repair or replace | |
| Worn shaker screen supports | Replace or repair | |
| Improper screen tensioning | Adjust screen tension | |
| Drilling fluid not added to system through shale shaker screens | Check all procedures for adding or returning drilling fluid (such as from trip tanks, etc.) | |
| No drilling fluid flowing to shale shaker | Valve closed | Open valve |
| Solids blocking valve or flow line | Locate and remove or clear blockage | |
| Bypass open | Open bypass. Check bell nipple for overflow. | |
| Shaker Screen failure | Within an hour | Heavy solids loading. Vibrators operating improperly. Coarse formations on fine screen cloths. |
| Within a few hours | Loose screen cloth; Missing tension bolts or locks; Vibrators operating improperly; Damaged shaker bed; Missing channel rubbers Improper tension. |
|
| Within a day | Damaged shaker bed; Inoperable vibrator; Extremely high mud weights; Misalignment of screens; Failure to maintain screen tension. | |
| Within a few days | Hematite used as a weighting agent; Worn channel rubbers; Worn side or cross supports; Bent drawbars. |
Common Causes of Shale Shaker Screen Failure:
- Personnel improperly trained on handling, storage, maintenance, and installation of deck rubber and screen assembly.
- Improper handling during installation—screens damaged before using.
- Deck rubber improperly installed.
- Improper tension during installation. Continuous screens should be retensioned within one-half hour of installation, every four hours during the first 24 hours of operation, and once per hour thereafter.
- Careless storage allowing grit and sand between layers on multiple screen assembly.
- Tension strip improperly seated in the screen hook strip.
- Deck rubber is worn, damaged, or dirty.
- Tension rails damaged allowing improper tensioning of the screen assembly or damaging of the hook strip.
- Dried cuttings and drilling fluid left on screen during shutdown of shaker.
- Cuttings accumulate under edge of screen.
- Tensioned screen assemblies on shaker used as worktables
- Improperly manufactured screen assemblies.
