Polyanionic cellulose LV HV

Polyanionic cellulose (PAC) is a water-soluble polymer that is derived from cellulose. It is widely used in the oil and gas industry as a drilling fluid additive, where it is used to control fluid loss, increase viscosity, and improve shale inhibition. PAC is available in different grades, with varying degrees of substitution and molecular weight. Two common grades of PAC are low viscosity (LV) and high viscosity (HV) PAC.

PAC LV has a low molecular weight and a low degree of substitution. It is used as a filtration control agent and as a rheology modifier in drilling fluids. LV-PAC has good solubility in water and is effective at low concentrations. It is also used as a viscosifier in cement slurries and as a stabilizer in emulsions.

PAC HV, on the other hand, has a higher molecular weight and a higher degree of substitution than LV-PAC. It is used as a primary viscosifier and fluid loss control agent in drilling fluids. HV-PAC can also be used as a secondary viscosifier in combination with other polymers. It has a high tolerance for salt and temperature, and is effective at high concentrations.

Both LV-PAC and HV-PAC are polyanionic, which means they carry a negative charge. This charge makes them effective at controlling fluid loss by forming a filter cake on the wellbore. The negative charge also makes them effective at inhibiting shale hydration and dispersion. PAC can also improve wellbore stability by preventing the migration of fines and clay particles.

In conclusion, polyanionic cellulose (PAC) is a versatile polymer that is used in the oil and gas industry as a drilling fluid additive. LV-PAC and HV-PAC are two common grades of PAC that are used for different purposes. LV-PAC is used as a filtration control agent and as a rheology modifier, while HV-PAC is used as a primary viscosifier and fluid loss control agent. Both grades of PAC are polyanionic and effective at controlling fluid loss and inhibiting shale hydration and dispersion.