CMC & PAC - Drilling Fluid Additives

During the drilling of exploration and production wells for oil & gas and water, CMC (Carboxymethyl Cellulose) & PAC (Polyanionic Cellulose) as being drilling fluid additives are used for two primary functions; to form a filter cake at the borehole wall in order to minimize the water loss and to control the rheology of the fluid system.

Drilling fluids are mainly water based or solvent based, today due to environmental and operational concerns most drilling wells are operated with water based drilling fluids. Since CMC and PAC are water soluble polymers, they are used in water based drilling fluids as mud performance increasing additives.

CMC and PAC added to the base mud by various preparation processes depending on the aimed achievement. After preparation of the fluid, the drilling mud is pumped from the mud tanks on the platform down the drill pipe, while cooling and lubricating the drilled bits by exiting the drill string from nozzles. Then the fluid rises upwards between the drill string and the formation wall, carrying the drilled solids to the surface. As long as the fluid’s technical properties allow, the same process repeated after purifying the fluid. In order to maintain such a proper fluid circulation along the well, CMC and PAC are used to control and manage the rheological properties of the fluid.

It is important that water loss to the soil along side the borehole would be kept under control as it has a direct effect on well production and operation efficiency.

Due to water retention abilities of CMC & PAC, the fluid minimizes the loss of water to the soil by suspending it. It is also essential to form a thin filter cake in order to prevent stuck pipe incidents.

Apart from above mentioned two main functions, CMC & PAC;
• Provide shale inhibition by preventing well bore against collapse due to their film forming properties.
• Improve the cooling and lubricating properties of the drilling fluid.
• Help protect the thermal and biological stability of the fluid.


CMC and PAC are biodegradable environmentally friendly non-toxic compatible drilling fluid additives which increase the performance of the fluid in order to properly carry out its functions.

USK Brand CMC & PAC Products for Drilling

Product Names

Product Classifications

 Industry Standards
USK – 20 PH CMC LV API & OCMA
USK – 1000 BY CMC HV API & OCMA
USK – 100 BY PAC LV API
USK – 500 BY PAC LV API
USK – 200 PP PAC LV API
USK – 10000 RT PAC R API
USK – 10000 RP PAC R API

Depending on the conditions of the well bore, desired achievement/efficiency and physical/chemical properties of the drilling mud, these products are either alone or in combination used with other drilling fluid additives in order to get the highest performance from the drilling itself.

UGUR SELULOZ KIMYA (USK) develops and manufactures different qualities of CMC & PAC and exports to world markets. Particularly drilling, minerals flotations, detergents, adhesives and water based paints quality CMC & PAC products are our specialties. Should you need more information plase feel free to conact us at export@uskcmc.com