On a weighted mud, a bank of desilters becomes a liability: barite is ground to pass 200 mesh (~74 µm and finer), squarely in the desilter cut range. Run bare desilters on weighted mud and you discard weight material you paid for. The mud cleaner solves exactly this problem.
What a mud cleaner is
A mud cleaner is a desilter bank with an underflow screen beneath the cone discharge. The cones make their usual silt-sized cut; the combined underflow drops onto a fine vibrating screen (150–200 mesh):
- Barite (passing 74 µm) passes through the screen and returns to the active system — recovered.
- Drilled silt (coarser than the screen cut) is retained and discharged as waste.
When to use it
| Mud type | Bare desilters? | Mud cleaner? |
|---|---|---|
| Unweighted WBM | Yes | Not needed |
| Weighted WBM or OBM | No — discards barite | Yes |
Screen selection
Standard range 150–200 mesh. Too fine: barite retained with silt. Too coarse: silt passes with barite. Watch the discard — bright heavy particles mean the screen is too coarse. Feed head still rules: cones need ~75 ft regardless of the screen beneath.
Key takeaways
Use bare desilters only on unweighted mud. On any programme with barite, the mud cleaner is the only way to run fine cyclone separation without eroding your own mud weight.