Instructions 1. Used for the loss strata of fractured layer and permeability large pore, DR-TC is 2-3% of the total plugging agent, the optimal dosage is 3%. 2. Used for plugging construction of complex leakage layer with ground water zone, DR-TC dosage is 3-4% of the total plugging agent. 3. Used for the permeability loss layer, as one additive of plugging drilling fluids, DR-TC dosage is 1-3% (t / 100 m3 drilling).