Bentonite is a kind of clay mineral with montmorillonite as the main component. It has strong water absorption, it can absorb 8 times of its own volume of water, and it has a volume expansion of 10-30 times. It is suspended and cemented in the aqueous solution. It has grease luster and smooth touch. it Can absorb water to expand and become colloidal shape. If the water  lost after long-term air drying, it can become loose again Because of its strong ion exchange capacity, bentonite can absorb or absorb various colors. Mix it with grease to make it smoother. Its fine powder water suspension has good dispersion and  not easy to precipitate. In oil and gas drilling, mud should be used to cool bit, remove debris, protect well wall and balance ground pressure. Bentonite is an ideal material for drilling mud because of its good dispersibility and large amount of mud.