Bentonites in drilling industry are used to carry the degraded materials in soil layers above to reduce friction by forming film layers inside the well to increase wearing resistance of the drilling bits.
API Spec 13A and TSE 977 standards are required for the bentonites to be used in this sector. Plastic viscosity should be min. 10 cps, fan viscosity should be min 30 cps (at 600rpm), filtrate volume should be max. 15 ml.