... water-base drilling fluids with the dosage of 1%-3%. propertyspecificationappearancefree-flowing powdermoisture, %≤ 1 0 .0pH7.0 ~ 10 .0relative expending ratio , %≤ 30 ... .0API fluid loss ,mLroom temperature≤ 1 0 .0200°C /Aging 16h≤ 12.0150 °C ,3 .5MPaHTHP ... fluid loss,mL≤ 2 8 .0Feature 1.Good shale inhibition 2.Good stability at high temperature, resistance ...