WATCH · Watch — trend and planMud system →Cost of fault ≈ $35k+ / incident
Why it matters
Failing suspension lets solids settle into beds and risks barite sag on weighted mud. Because the agitator ‘still runs', the loss of coverage is usually blamed on the mud or the guns until a settled bed appears.
Likely causes
Impeller blade wear from abrasive solids — the normal wear path.
Agitator undersized for the tank / mud weight from the start.
High abrasive content accelerating blade wear.
Heavy mud needing more agitation than worn blades provide.
Coarse solids speeding blade erosion.
How to diagnose it
Inspect blade condition and profile.
Compare surface agitation pattern across tanks.
Probe for settling beneath the agitator.
Check gearbox / shaft for play or noise.
Confirm the agitator is sized for the tank and mud weight.
The fix — step by step
Replace worn / bent impeller blades.
Right-size the agitator if it was always marginal for the duty.
Service the gearbox / shaft restoring full rotation.
Re-establish full coverage; support with mud guns on the bottom.
Use abrasion-resistant blades on abrasive / weighted mud.
Confirm it's fixed
✓ Verify: Full surface agitation pattern restored with no settled bed beneath the agitator.
Field note. ‘The agitator's running' is not ‘the tank's agitated.’ Worn blades turn at full speed and move almost nothing — so the first sign is a settling bed, not a stopped motor. Judge the agitator by the pattern on the surface and the absence of a bed, not by the fact that the shaft is spinning.