WATCH · Watch — trend and planMud system →Cost of fault ≈ $30k+ / incident
Why it matters
Eroded guns quietly stop doing their job: agitation drops, dead zones form, and solids settle — often blamed on agitators while the real cause is a washed-out nozzle no longer sweeping the bottom.
Likely causes
Nozzle wear from abrasive solids at high velocity — the normal wear path.
Wrong nozzle material for an abrasive mud.
Running guns continuously at high pressure on abrasive mud.
No inspection / replacement schedule — run to failure.
High abrasive (sand) content accelerating wash.
Weighted mud (barite) increasing erosion.
Coarse, abrasive drilled solids in the active system.
How to diagnose it
Inspect nozzle bore for wear / enlargement.
Compare jet strength and sweep gun-to-gun.
Trend header pressure for a drift down.
Check for settling near suspect guns.
Confirm nozzle material suits the mud's abrasiveness.
The fix — step by step
Replace eroded nozzles on a schedule, not at failure.
Use harder nozzle material for abrasive / weighted mud.
Maintain header pressure for an effective sweep.
Re-aim renewed guns to cover bottoms and corners.
Reduce abrasive load upstream where possible (better SC removal).
Confirm it's fixed
✓ Verify: A tight, full sweep restored from each gun, header pressure back in band, and no settling near the guns.
Field note. When a corner starts settling, people reach for the agitator — but check the mud gun first. A washed-out nozzle loses its sweep long before anyone notices, and a cheap nozzle change often fixes a ‘dead zone' that looked like an agitation problem.