Polyanionic cellulose, high viscosity (PACHV) is a type of sodium salt of carboxymethyl cellulose with an increased degree of substitution.
In the process of drilling production and production oil, gas and water wells, polyanionic cellulose (PAC) used as additives for drilling fluids perform two functions - it creates a filter layer at the wellbore walls to minimize water loss and controls the rheology of fluid systems.
The basis of drilling fluids can be both water and organic solvents, however, today's environmental protection requirements and technological features of well drilling processes determine the use of water-based drilling fluids in most cases.
Since PAC is a water-soluble polymer, it is used in drilling fluids as a performance enhancer. Unlike CMC, PAC is more effective in saline solutions.
Polyanionic cellulose, low viscosity (PACLV)
High-viscosity polyanionic cellulose is used to increase the relative viscosity and decrease the filtration rate of clay-free solutions and solutions with a low solid phase.
It is effective as a stabilizing agent in all types of water-based drilling fluids, provides stabilization of the borehole walls when drilling shale, and helps to reduce the solid phase in the drilling fluid. Reduces filtration rate.
Forms a thin and elastic filter cake, which allows to reduce losses of drilling fluid, maximally preserve the diameter of the annular space and reduce hydraulic resistance in the wellbore. It is thermostable and stable in highly mineralized environments (saturated solutions of sodium and potassium chlorides).
The shelf life is 12 months from the date of production.