Polyanionic cellulose R

Viscosity and rheological properties: The viscosity of PAC is derived from its degree of polymerization, which directly determines the apparent viscosity, dynamic shear force and gel strength of the drilling fluid, and affects the cutting-carrying capacity and wellbore cleaning ability. The high-viscosity model (PAC-HV) significantly increases viscosity, while the low-viscosity model (PAC-LV) mainly provides filter loss control.

Degree of substitution and salt resistance: Degree of substitution (DS) is a key indicator for measuring the number of carboxymethyl substitutions on each glucose unit. The higher the DS (usually ≥0.90), the stronger the salt resistance and calcium and magnesium resistance, and the better the filtration loss control ability. The salt-to-viscosity ratio (SVR) is a direct indicator for measuring salt resistance. The higher the SVR, the higher the viscosity retention rate in salt water.

Filtration loss control: PAC reduces filtration loss by adsorbing onto clay particles to form a hydration film and a spatial network structure, thereby creating a dense mud cake. Its effect is directly related to the degree of substitution, purity and the amount used in the system.

Thermal stability and environmental friendliness: The thermal stability of conventional PAC can reach over 130℃, and some research on modified products attempts to increase the application temperature to over 200℃. PAC itself is non-toxic and biodegradable, and it is an environmentally friendly treatment agent

Exceptional Salt & Hardness Tolerance: PAC-R's primary distinguishing feature is its ability to maintain performance in saline environments. Its high and uniform Degree of Substitution (DS) enhances its salt viscosity ratio (SVR), a key measure of salt resistance. It can function effectively in saturated brine and in the presence of high calcium/magnesium hardness.

Reliable Filtration Control: It acts as an efficient fluid-loss reducer by forming a thin, low-permeability filter cake, even in challenging salt and gypsum formations.

Thermal Stability: PAC-R offers good thermal stability, with specifications often citing performance after hot rolling at 130°C (266°F). Research indicates PAC materials maintain properties in high-pressure, high-temperature (HPHT) conditions, though performance above 200°C (392°F) may be limited without modification.

Rheological Modification: It provides effective viscosity building and rheological control (increases apparent viscosity, plastic viscosity, and yield point), which is crucial for hole cleaning and suspension of cuttings in weighted, salt-saturated muds.

Shale Inhibition & Environmental Safety: It helps stabilize reactive shale formations and is known for being non-toxic, biodegradable, and environmentally friendly compared to many synthetic polymers.