Filtration Control: Causticized lignite forms a thin, low-permeability filter cake on the wellbore wall, preventing excessive fluid loss into porous formations.
Rheology Modification: It can improve the rheological properties of drilling fluids, such as viscosity and gel strength, which are crucial for carrying and suspending drilled cuttings and maintaining wellbore stability.
Shale Inhibition: Causticized lignite has shale inhibition properties, which help prevent the swelling and disintegration of shale formations, reducing the risk of wellbore instability and stuck pipe incidents.
Temperature Stability: It exhibits good thermal stability, making it suitable for use in high-temperature drilling environments.