Drilling Fluid Additives

Additives that build and control viscosity and gel strength so the mud suspends cuttings and weighting material, including bentonite clay and biopolymers such as xanthan gum. They govern the fluid's shear-thinning behavior across the circulating system.

Water-soluble polymers that reduce fluid loss into permeable formations and build a thin, low-permeability filter cake. Common products are polyanionic cellulose (PAC) and carboxymethyl cellulose (CMC) supplied in low-viscosity (LV) and regular grades.

Chemicals that suppress hydration and swelling of reactive clays and shales to maintain wellbore stability. They include inorganic salts (e.g., potassium chloride), amine-based inhibitors, and polymeric clay stabilizers.

Deflocculants that lower viscosity and gel strength by dispersing clay particles, improving flow and pumpability. Examples include lignosulfonates, lignite (causticized leonardite), and polyphosphate-based thinners.

Additives that reduce torque, drag, and friction between the drill string, casing, and formation, used heavily in directional and high-angle wells. They are supplied as liquid or solid (bead) lubricants for water- and oil-based systems.

Surfactants that stabilize water-in-oil emulsions in oil-based and synthetic-based muds and oil-wet solids and weighting agents. Primary and secondary emulsifiers together maintain emulsion stability and electrical stability.

Chemicals that protect the drill string and casing from corrosion caused by dissolved oxygen, carbon dioxide, and hydrogen sulfide. They include filming amine inhibitors, oxygen scavengers, and H2S scavengers.

Pregelatinized and modified starch products used mainly for filtration control in high-salinity and saturated brine systems where cellulosic polymers are less effective. They are biodegradable and compatible with reservoir-drill-in fluids.