THE FUNCTION OF CMC & PAC IN THE OIL DRILLING INDUSTRY
CMC or Polyanionic Cellulose (PAC) is a key ingredient in drilling fluids used in the oil and gas industry. They are used for two primary functions as drilling fluid additives: 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. As 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 alongside 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

Typical CMC & PAC products for oil drilling application:
CMC LV
CMC HV
PAC LV(API)
PAC HV(API)
PAC R(API)
Note: Specific specs can be customized according to client’s detailed requirements