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PAC-R vs PAC-UL vs PAC-LV: Which Grade for Your Mud System?

All three grades are high-purity polyanionic cellulose for fluid-loss control in water-based mud. The difference between them is how much viscosity each one contributes to the system, which determines which grade fits your solids loading and rheology targets.

GradeProduct CodeViscosity ContributionBest-Fit System
PAC-R (Regular)PZT-PAC-RModerateGeneral-purpose WBM where some added viscosity is acceptable or desired
PAC-LV (Low Viscosity)PZT-PAC-LVModerate-low (between UL and R)Systems needing a controlled, moderate viscosity contribution alongside fluid-loss control
PAC-UL (Ultra-Low Viscosity)PZT-PAC-ULMinimalAlready-viscous or high-solids systems where any further thickening is a liability

When to reach for PAC-R

Regular-grade PAC providing efficient general-purpose filtration control with a moderate contribution to system viscosity. This is the default starting point for most WBM programs. Pick a different grade only when the system's existing viscosity or solids content pushes you toward UL or LV instead.

When to reach for PAC-LV

Mid-range PAC grade balancing fluid-loss control with a moderate, controlled viscosity contribution between UL and R grades. A middle-ground choice when you want more predictable fluid-loss performance than UL provides, without the full viscosity contribution of R.

When to reach for PAC-UL

The lowest-viscosity grade in the PAC family: fluid-loss control with minimal added viscosity, for already-viscous or high-solids systems. The right call whenever the mud is already carrying enough solids or viscosity that any additional thickening becomes an operational problem rather than a benefit.

Frequently Asked
Which PAC grade should I use in a high-solids system?
PAC-UL (Ultra-Low Viscosity) is generally the better fit for already-viscous or high-solids systems, since it adds minimal viscosity while still delivering fluid-loss control. Using PAC-R in that same system risks over-thickening the mud.
Can PAC grades be blended or switched mid-well?
All three grades ship under the same PAC product family and are compatible with each other, so a mud engineer can transition between grades (or blend them) as solids loading and viscosity targets change through a well's sections. Contact Petriz for grade-specific TDS/SDS before making a field change.
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Petriz Technical TeamWritten by the Petriz technical team and cross-referenced against API and ISO 13A specifications, published supplier documentation, and SPE literature. General guidance only: confirm dosing and compatibility against the current product TDS and your own testing before field application.