Product overview
Drilling-grade sodium CMC is used in water-based drilling fluids for filtration control and viscosity. Low-viscosity (LV) grades mainly reduce fluid loss; high-viscosity (HV) grades also build viscosity and help carry cuttings. For salt-saturated muds, polyanionic cellulose (PAC) is usually the better choice.
Grades and specification
| Property | LV1 | LV2 | HV1 | HV2 | HV3 |
|---|---|---|---|---|---|
| Degree of substitution | ≥ 0.80 | ≥ 0.80 | ≥ 0.65 | ≥ 0.80 | ≥ 0.80 |
| Purity | 70–75% | 80–85% | ≥ 85% | ≥ 80% | ≥ 90% |
| Moisture | ≤ 10% | ≤ 10% | ≤ 10% | ≤ 10% | ≤ 10% |
| pH | — | — | 7–9 | 7–9 | 7–9 |
| Bulk density | 370–420 g/L | 370–420 g/L | 370–420 g/L | 370–420 g/L | 370–420 g/L |
Viscosity, fluid-loss and Fann 600 rpm readings in fresh water, 4% salt water and saturated salt water are measured in prepared muds. We send these results with the TDS for the grade you select. Values are from our current product data. Confirm the exact grade and limits with the TDS and the COA of the lot you test.
Applications
- Water-based drilling muds: filtration control and a thin, low-permeability filter cake
- Workover and completion fluids: viscosity and fluid-loss control
- Water-well and civil drilling: borehole stability and cuttings transport
How CMC controls fluid loss
When drilling fluid is pushed against a permeable formation, water filters into the rock and leaves a filter cake on the wall. CMC chains adsorb on clay particles and plug the pores of the cake, so the cake is thinner and less permeable and less water is lost. HV grades also raise the viscosity of the fluid, which helps carry cuttings to the surface.
| CMC LV | CMC HV | PAC LV / HV | |
|---|---|---|---|
| Main job | Fluid-loss control | Fluid loss and viscosity | Fluid loss (LV); fluid loss and viscosity (HV) |
| Fresh-water muds | Good | Good | Good |
| Sea water and salt muds | Limited | Limited | Preferred |
| Cost | Lowest | Low | Higher |
CMC is most cost-effective in fresh-water and low-salt systems. In sea-water or saturated-salt muds, or where calcium is high, PAC usually performs better per kilogram.
How to choose a grade
Use LV grades when the mud already has enough viscosity and you only need fluid-loss control; use HV grades in low-solids muds that need viscosity too. Test in your own base fluid and salinity, and compare with PAC in high-salt systems.
Packing and documents
25 kg multi-wall paper bags with an inner PE liner. Other packing is agreed per order. TDS, SDS and a representative COA are available for every grade, and each lot ships with its COA. Request documents or a sample.
Download (2026 revision): Technical data sheet (TDS, PDF) · Safety data sheet (SDS, PDF)
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FAQ
CMC or PAC for my mud?
CMC is cost-effective in fresh-water and low-salt muds. PAC tolerates salt and hardness better and is usually chosen for sea-water and saturated-salt systems.
Do you have API test data?
Yes. Ask for the mud test data with the TDS of the grade you are evaluating.
What dosage of CMC is used in drilling mud?
It depends on the mud and the fluid-loss target. Run API filtration tests on your own base fluid; we send mud test data for the grade with the TDS.
What temperature can CMC handle?
CMC is a cellulose polymer and starts to degrade at elevated bottom-hole temperatures; above roughly 120–150 °C formulators switch to synthetic polymers or add stabilisers.