PAC (Polyanionic Cellulose)
Polyanionic Cellulose (PAC) is a water-soluble polymer that provides fl uid-loss control properties, shale inhibition, and salt tolerance. It is a drilling fl uid additive and it is also used in completion fl uids as a thickener for low density brines. PAC requires small concentrations to e ffectively reduce filtration rates and/or reduce and stabilize rheology and can be used in drilling fl uids having a broad range of salinity, pH, and total solids content.
Polyanionic Cellulose (PAC) -HV is used for water-based drilling fl uids. It reduces the fi ltration rate of many water-based oil and gas drilling fl uids, increases and stabilizes the viscosity, and improves the hole cleaning and suspension properties in a wide variety of fluid environments.
Polyanionic Cellulose (PAC) -LV is used for solids-laden and water-based drilling fl uids. It reduces the fi ltration rate of many water-based drilling fluids, especially solids-laden fl uids, without causing signi cant increases in viscosity or gel strengths. Small amounts can reduce and stabilize the rheology of fl occulated and/or solids-laden fl uids.
| PAC-LV Low Viscosity | PAC-HV High Viscosity |
|
|---|---|---|
| Moisture (mass fraction) % | ≤ 10 | ≤ 10 |
| Apparent Viscosity ( MPa·s) | ≤ 40 | ≥ 50 |
| Degree of Substitution | ≥ 0.90 | ≥ 0.90 |
| API Fluid Loss | ≤ 40 | ≤ 23 |
| Viscosity Brookfield 1% | ≤ 50 | ≥ 1,200 |
| pH of 2% Solution | 6.0 - 8.0 | 6.0 - 8.0 |