drilling 13 Flashcards
Such as bentonite or polymer additives, are used to increase the viscosity
of the fluid, aiding in the suspension of cuttings and providing hole cleaning.
Viscosifiers
Such as lignosulfonates, phosphates, or polyacrylates, prevent
excessive viscosity by dispersing particles in the fluid, particularly in high-solid or hightemperature environments.
Thinners/ Dispersants
Caustic soda (sodium hydroxide) and potassium hydroxide are
used to maintain an alkaline pH in the fluid, preventing corrosion and enhancing the
stability of certain additives.
pH Control Agents
Potassium chloride (KCl), glycol, or silicate additives inhibit shale
swelling and hydration by reducing water interaction with clay minerals.
Shale Inhibitors:
Polymers like PAC (polyanionic cellulose) and starch reduce
fluid loss by creating a thin filter cake on the wellbore wall.
Filtration Control Agents:
Amines or phosphates prevent corrosion of metal surfaces by
forming a protective film or controlling pH and oxygen levels.
Corrosion Inhibitors
Additives that reduce friction between the drill string and the wellbore,
commonly used in directional and horizontal drilling.
Lubricants
Chemicals like glutaraldehyde are added to prevent bacterial growth,
especially in water-based fluids, which can degrade fluid additives and cause fouling.
Biocides:
